ZXTape! 0Created with Ramsoft MakeTZXph4 mJh,m6:6:0: physics help tape 4  G C E Tutoring  June 1984 !w(25,8):2000 r(10 ) t(5):9069m# Lscrhdr=9300T$:qsthdr=9350$:endsec=9400$:getans=9450$ fig2=8950":fig=9030F#:axes2=9000(#:eg=9040P#:axes=9100#:triangle=9150#:diagram=218:praise=9720% $grax=7000X:linear=7050 5br=8100:squrec=8850":squpar=8900" 1:" PHYSICS help ph4":" Mechanics" #:"  G C E Tutoring June 1984" 2t:"Hello, what's your name ?":n$:n$:"OK, ";n$;",":"I'll begin by telling you how touse this physics program." 4S:"This tape covers 6 subjects which all come under the headingof mechanics." :>:"Press the key marked C so I can type the next screenfull" <a$=:a$="c"62> = 60< >:z=1100d:z AF:"Thanks. From now on when I want you to press the C key, I'll say" D:" Hit C to continue" F4:"Here's the list of subjects on this program": H"scalars and vectors hooke's law kinetic energy and momentum newton's laws equations of motion graphical representation" K2:"Which subject do you want to try ?":s$: Lc$=s$ N'(s$)>3s$=s$(13) Os$="sca"1700 Ps$="hoo"200 Qs$="kin" 300, Rs$="new"400 Ss$="equ"500 Ts$="gra"900 ^Cs$"sca"s$"Hoo"s$"Kin"s$"New"s$"Equ"s$"Gra"9200# _ 70F c d f    Hooke's law  "Hooke's law": ?"Hooke's law is to do with springs. It states that :": >"Strains are proportional to the stresses producing them.": w"Strain is the amount an elastic material stretches when it undergoes a load. It is a ratio,and has no units.": ~"strain = length 1 / length 2 where length 1 = under stress and length 2 = at rest": scrhdr "eg. A spring at rest has a length of 10cm. Under a load of 1kg it extends to 15cm. How long would it be under a load of 2kg ? ": "extension (1kg) = 15-10 = 5cm extension (2kg) = 2 x ext(1kg) = 2 x 5cm = 10cm so total length = 10cm+10cm=20cm" scrhdr qsthdr @"A spring at rest has a length of ";r(1)*2;" cm" a"Under a load of ";r(2);" kg it extends to ";r(1)*2+r(3)*2;" cm." :"What is its length under a load of ";r(4);" kg ?" hexp=r(1)*2+r(4)*r(3)*2/r(2):egc=3:return=245:getans "More questions ? (Y or N)": q$:q$ $q$(11)="y"232 )2n$=c$:start=200:return=298*:endsec * + , . 1K.E. and momentum 4 6!"Kinetic energy and momentum": 8D"The momentum of an object is theproduct of its mass and velocity" ;":"momentum = mass x velocity": >]"Here is a table of common-place objects and the amount of momentum they posess : ": ?7:0 @" Object vel mass momentum":5:0:" car 66mph 30ms 1000kg 30000Ns bike 22mph 10ms 80kg 800Ns bottle 5ms 5kg 5Ns tossed coin 3ms 0.01kg .03Ns " A6:0 Bscrhdr EB"Kinetic energy is the energy that a moving body posesses.": H"To lift an object - eg. a rock -to a certain height requires a specific amount of energy. The amount depends on the mass of the object and the height to which it is lifted.": J"While the object is stationary it posesses POTENTIAL energy. This is translated into kinetic energy if the object is dropped." Lscrhdr OQ"Here is a table of common-place objects and the kinetic energy they have :": P0:7 R&:"object mass vel K.E. " T 5 V" car 1000kg 30ms 450 000bike 80kg 10ms 4 000bullet 0.01kg 400ms 800air-gun 0.001kg 142ms 10fly 0.0001kg 2ms 0.0002" Y0:6 \ ^W"Kinetic energy is calculated by multiplying half the mass by thesquare of velocity." _ 7 `&:"K.E. = 1/2 mass x (velocity) " a 6 cscrhdr f`"Here is an example of a calculation to find the kinetic energy of a moving object.": hw"A brick is thrown at 10ms by a demonstrator. If the brick has a mass of 4kg, what is its kinetic energy ? ": j&"K.E. = 1/2 x 4 x (10) = 200J ": mqsthdr pt"What is the kinetic energy of anobject of mass ";r(1);"kg if it is travelling at ";r(2);"ms ?": r.exp=r(1)*r(2)*r(2)/2 t'egc=3:return=375w:getans w9"More questions ? (Y or N)":b$:b$:b$="y"365m zscrhdr ;start=300,:return=398:n$="K.E. and momentum" endsec 2n$=c$:start=300,:return=398:endsec     Newton's laws  :"Newton's laws": &"There are three laws of motion :": t"1. A moving body will travel in a straight line at a constant velocity, unless acted upon by a force.": u"2. The rate of change of momentum of a moving body is proportional to the force acting on it": ;"3. Every action has an equal and opposite reaction.": 4"What do these mean ? Let's take them one by one." scrhdr t"1. A moving body will travel in a straight line at a constant velocity, unless acted upon by a force.": "This is very important. Many people never really understand it. What it means is that an object which is already moving will :": ="a) carry on indefinately b) not change direction": scrhdr "Unless acted upon by a force. Onearth there are two things whichwe take for granted, but confuseus when we attempt physics questions. They are :": 0"a) air resistance b) gravity": "Both of these exert a force on amoving object. Air resistance makes it slow down, and gravity makes it follow a curved path.": scrhdr S"If they are not present then events are easier to follow, eg. in space.": "eg. A spacecraft travelling along when its rocket motor goes wrong. IT DOES NOT STOP, as there is no force making it stop." .:"No air, so no friction, so no force.": scrhdr u"2. The rate of change of momentum of a moving body is proportional to the force acting on it": ć"When you push a car on level ground it resists you. Many people will tell you that you ""have to overcome the inertia"" ": "They are a bit confused.": scrhdr "What you are actually doing is increasing the car's momentum. Momentum can be thought of as something which a moving object posesses which has to be taken away in order to stop it, or something which a stationary object does not have which must be supplied for it to move."  Θ"The rate at which you change themomentum depends on the law : the more force, the quicker the momentum builds up, and the faster the car goes." 4:"For more details see the sectionon momentum.": scrhdr ;"3. Every action has an equal and opposite reaction.":  "The car in the previous example is a good example of this law. When you push the car, it resists you by exerting a force equal to the one pushing it. If it didn't, you wouldn't be able to feel its presence, as the moment you touched it, it would move.":  scrhdr C"This law is very important in spaceflight. A rocket motor works by making a very large amount of gas go extremely fast in the opposite direction to that of the spacecraft. Accelerating this gas requires supplying a force to it. The equal and opposite force makes the spacecraft move forwards.": I"The exhaust gas DOES NOT push against the air or anything else." scrhdr:qsthdr &"Newton's first law states that :": ;"1. A moving body will travel in a straight line at constant velocity unless acted upon by a force 2. Every action has an equal and opposite reaction 3. Force is equal to the rate of change of momentum": 4exp=1:egc=3:return=490:getans '"Newton's second law states that :": ;"1. A moving body will travel in a straight line at constant velocity unless acted upon by a force 2. Every action has an equal and opposite reaction 3. Force is equal to the rate of change of momentum": 4exp=3:egc=3:return=493:getans &"Newton's third law states that :": ;"1. A moving body will travel in a straight line at constant velocity unless acted upon by a force 2. Every action has an equal and opposite reaction 3. Force is equal to the rate of change of momentum": 4exp=2:egc=3:return=496:getans scrhdr 2n$=c$:start=400:return=498:endsec     eqs of motion  "Equations of motion": "There are four important equations of motion. They all involve quantities such as velocity, acceleration, time anddistance. For short, these are written as follows :": "u = initial velocity v = final velocity a = acceleration t = time (seconds) s = distance (metres)" scrhdr  :"Here are the equations :": u"1. v=u+at 2. s=1/2(t(u+v)) 3. v=u+2as 4. s =ut+1/2(at)"  #:"Let's take these one by one :"  scrhdr "1. v=u+at": w"A sports car accelerates at 4ms^2 for 6 seconds from a standing start. What is its final velocity ? ": 9"u=0ms a=4ms^-2 t=6s"::"v=0+4x6=24ms (about 52mph)" scrhdr "2. s=t(u+v)/2": X"How far did the sports car in the last example travel before it reached 24ms ?": "v=24ms u=0ms t=6s": !"s=6(0+24)/2=72m" $scrhdr &"3. v=u+2as": ({"This equation is very similar to the first one, except insteadof needing to know u,a and t, u,a and s are required.": +w"eg. A stone is dropped off a 20m high building. What velocity has it attained when it hits the ground ? ": .%"s=20m a=10ms^-2 u=0ms ": 0"v=400 so v=20ms" 2scrhdr 5"4. s=ut+at/2": 8y"This equation is similar to the second one, except instead of needing to know t,u and v, t,u and a are required.": :q"eg. A stone is dropped down a well. It takes 3s to hit the bottom. How deep is the well ? ": <"u=0ms t=3s a=10ms^-2": ?"s=0+10x(3)/2=45m" Bscrhdr Dqsthdr F}"A car accelerates at ";r(1);" ms for ";r(2);" seconds from a standing start. What is the final velocity ?": HBexp=r(1)*r(2):egc=3:return=586J:getans Iscrhdr J"A stone is dropped from a heightof ";r(1)*10 ;" m. What is its velocity when it hits the ground ? (a=10ms)": LMexp=(200*r(1))^0.5:egc=3:return=590N:getans Nscrhdr U2n$=c$:start=500:return=598V:endsec V W X Z `      " ( z;start=600X:return=898:n$="matrix arithmetic" endsec     graphical representation   :"Graphical representation": p"The movement of any object (in physics the object is called ""a body"") can be represented on a graph.": l"On the x axis, time is shown. Onthe y axis, either distance, velocity or acceleration can be shown.": scrhdr  y$="vel" grax linear "This shows that as time progressed, the body's velocity increased. The straight line shows that it increased at the same rate - this is called UNIFORM acceleration.": scrhdr  y$="vel"  grax:linear:16,0 "This shows that velocity increased uniformly until t=5s, when acceleration fell to 0. From this time on, the velocity was constant.": scrhdr  y$="acc" grax '18,130:100d,0 |"This shows a constant acceleration, as in the first example. (The rate of change of velocity is constant.)": scrhdr  y$="acc" grax 918,130:83S,0:0,-30 "This shows a body under uniform acceleration until t=5s, as in the second example. After t=5s, the acceleration fell to zero, so the velocity remained constant." scrhdr 2n$=c$:start=900:return=998:endsec      N T    x z     @ B H   scalars and vectors  :"Scalars and vectors": }"Quantities such as mass, volume and length are called SCALAR quantities. Scalar quanties havesize but not direction.": z"Quantities such as velocity and acceleration have both size and direction. This type of quantityis called a vector.": D"The general property of a vectoris that it has two components.": scrhdr ¼ "The two components are magnitudeand direction. Velocity is a vector quantity having magnitude(speed) and direction. Speed is a scalar quantity, having no direction component.":  scrhdr qsthdr 1:"Which of these is a vector quantity ? " S:"1. length 2. time 3. velocity": 5exp=3:egc=3:return=1760:getans scrhdr 4n$=c$:start=1700:return=1798:endsec      vector arith. & laws  ":"Vector arithmetic and laws": ^"Vector arithmetic is very simpleand follows the laws of conventional arithmetic.": "Addition": <"Two vectors a and b add to make a vector c as follows:": ""a = 2 b = 3":" 1 4" 8i=12 :x=29:y=63?:br:x=93]:br &:"c = 2+3 = 5":" 1+4 = 5" x=101e:y=39':br  x=39':i=24:br !scrhdr $""a = 2 b = 3":" 1 4" &&:"c = 2+3 = 5":" 1+4 = 5" '9i=12 :x=29:y=151:br:x=93]:br (n:"Vector addition is commutative since it makes no difference which way round the vectors are added.": )&x=101e:y=39'+88X:br *x=39':i=24:br +"a + b = b + a = c": ."This is easy to see if you thinkof the vectors as position vectors. It makes no difference which one is taken first - the final position is the same." 0scrhdr 2"vector addition is also associative. Three vectors a, b and c add to make the same result in both of the following ways:": 54" d = a + (b + c) d = (a + b) + c" 8_:"Again, this can be easily understood if the vectors are thought of as positional." :3:"Vector subtraction is also conventional." <scrhdr ?"Vector multiplication": B/"A vector can be multiplied by a scalar:": D1" eg. a = 2 1": F:" eg. 2a = 2 x 2 = 4 2 x 1 = 2" GFi=12 :x=165:y=87W:br:x=77M:y=111o:br H(i=44,:x=85U:y=87W:br Iscrhdr Lqsthdr N/:"Is vector addition commutative ?":a$:a$ P;a$="No"a$="no""Yes it is ! Read the section again." Sa$="yes"a$="Yes"praise V(:"Is vector addition associative ?": X a$:a$ Z;a$="No"a$="no""Yes it is ! Read the section again." ]a$="yes"a$="Yes"praise b=n$="vector arithmetic":start=1800:return=1898j gendsec j k l n qvelocity triangles t v:"Velocity triangles"::"Sometimes it is necessary to know the length of a vector rather than its individual components.": x"Since the two components of a positional vector are at right angles to each other, the lengthof a vector can be calculated using Pythagoras' theorem." yscrhdr {:"For example, the length of a vector:"::" 4":" 3":::::::::"is 5. This can be seen in the triangle above." }1x=14-1:y=119w:i=12 :br ~label=0:triangle O"AB represent a the x component and BC the y component. AC is the length." scrhdr "The length of the vector can represent quantites such as speed. If an aircraft is flying at right angles to the wind its ground speed can be calculated using vectors:":  triangle q"AB represents the aircraft's airspeed, BC represents the wind velocity and AC represents the ground speed." 8,17;"air speed=150":10 ,17;"wind speed=80":12 ,17;"AC=150+80":12 +1,20;"AC=28900":14,21;"AC=170"  :::: scrhdr "Sometimes velocities will not be at right angles. In these cases Puthagorus cannot be used as the resultant triangle is not right angled." d:"The length can be calculated in these cases by drawing the triangle and measuring length." >n$="velocity triangles":start=1900l:return=1998 endsec   x$="": o=1̱x$ n=18 #w(o,n):x$(oo)+n-1,w(o,n) n o  H24,16,16,32 ,16,16,24,0 C24,8,8,4,8,8,24,0 F0,0,62>,64@,64@,64@,62>,0 E0,0,124|,2,2,2,124|,0 G0,66B,66B,66B,66B,66B,44,,0 G0,44,,66B,66B,66B,66B,66B,0  G0,0,60<,64@,124|,64@,60<,0 I240,8,120x,128,248,0,0,0 C0,0,0,4,126~,4,0,0 I248,136,136,136,0,0,0,0 C4,4,228,4,0,0,0,0 G240,8,240,8,240,0,0,0 G28,20,16,16,8,8,40(,568  E4,68D,228,68D,0,0,0,0 "G16,16,16,0,0,480,72H,480 %E12 ,18,18,12 ,0,0,0,0 (E7,4,4,8,8,144,80P,32 *G4,8,16,16,16,32 ,32 ,32 ,G32 ,32 ,32 ,16,16,16,8,4 /C32 ,16,8,8,8,4,4,4 2C4,4,4,8,8,8,16,32 4 )::(40(*3.14159Iρ/180)  z=31000 %v=((z^2-(z-1)^2)) u=v^0.5 C((u)-(u+0.5))<0.01z# =z;":";z-1;":";v^0.5 z  z=07 z:7-z 7x=13:"" c=110 :c x z 0::" G C E TUTORING"::" Orders"  Xgrax [1,0;"(";y$;")" ]M18,100d:100d,0:18,100d:0,58: `$10 ,2;"0 1 2 3 4 5 6 " b10 ,16;"(time)" :  linear '18,100d:83S,46.  @"A geometric figure can be rotated by multiplying the individual coordinates by one ofthree different transformation matrices, depending on whether rotation through 90,180 or 270 is required.": B&"For a 90 rotation, multiply by:": E" 0 -1":" 1 0": H,"A 90 rotation is shoen in the diagram." I J:"The coordinates of the corners of the triangle are:": L&" 2 2 3":" 2 1 1": MM"which when multiplied by the matrix for a 90 rotation become:": N?" 0 -1 2 0-3 -3 1 0 3 2+0 2": O?" 0 -1 2 0-1 -1 1 0 1 2+0 2": P=" 0 -1 3 0-1 -1 1 0 1 3-0 3" R scrhdr:  Gx,y:0,16,-/3:x+i,y:0,16,/3: "There is a special matrix calledthe UNIT or identity matrix. If another matrix is multiplied by it there is no effect, rather like multiplying a number by 1 in ordinary arithmetic." $:"This is the 2x2 unit matrix:": " 1 0":" 0 1": 'x=8:i=24:y=80P:br scrhdr  " "square + rectangle "]27,568:502,0:0,502:-502,0:0,-502 "_27,568:100d,0:0,502:-100d,0:0,-502 "$7,2;"A D F" "%15,2;"B C E" " " "square + parallelogram "]27,568:75K,0:0,502:-75K,0:0,-502 "`27,568:75K,0:25,502:-75K,0:-25,-502 "#7,3;"A E D F" "!15,3;"B C" " " #K27,568:110n,0:568,41):0,557 #f15,7;"0":15,9 ;"2":15,11 ;"4":15,12 +1;"6" #E14,6;"0":12 ,6;"2":10 ,6;"4" #K27,568:110n,0:568,41):0,557 # [568+16,568+8:0,16:8,-16:-8,0 # ^568+32 ,568+16:0,32 :16,-32 :-16,0 #\568-10 ,568+16:-16,0:16,8:0,-8 #11 ,9 ;"A" #9 ,12 ;"B" #11 ,4;"C" #& #' #( #2K27,41):110n,0:27,41):0,557 #:]17,3;"0":17,6;"2":17,9 ;"4":17,12 ;"6" #<17,15;"8" #>\16,2;"0":14,2;"2":12 ,2;"4":10 ,2;"6" #A #Fi579+x,513+y:20,20:-20,20:-20,-20:20,-20: #Hc72H+x,568+y:0,30:-30,0:0,-30:30,0: #P'"Here is an example of ";n$ #R #Z #\ #_noises #b #d-z=120:0.01z# =,-24:z #f #h #i&z=15:0.3,t(z):z #l #mz=15:t(z):z: #n*7,9 ,5,-7,0 # # # #axes # #_30,90Z:210,0:30,90Z:0,557:0,-110n #10 ,2;"0" #f11 ,9 ;"90":11 ,15;"180":11 ,22;"270":11 ,29;"360" #atype=09124# #atype=19130# #.4,2;"1":16,1;"-1" #07,1;".5":13 ,0;"-.5" # #.7,2;"1":13 ,1;"-1" #.4,2;"2":16,1;"-2" # # # #draw triangle # #N30,60<:100d,0:0,60<:-100d,-60< #label=09175# #15,6;"adjacent" # 8,1;"hypoteneuse" #11 ,18;"opposite" #6123{,60<:0,7:7,0 #H41),60<:0,2:-3,2:-2,0 #14,2;"A" #14,17;"B" #6,17;"C" #::::::::: # # # #"Berk ! What's ";c$;" ?": #'"Wally ! ";c$;" isn't on the tape.": ##"Moron ! Try spelling straight": #"sorry, ";n$;" ? ": #"Are you tired, ";n$;" ?": #"Don't wind me up, ";n$: $T $V scrhdr() $Y $\9900&:: $ $ qsthdr() $ $'9600%:9900&:egc=0: $ $ $endsec(start,n$) $ $5"That finishes ";n$:"Hit r to repeat this section" $ 9900& $a$="r"start $return $ $ $getans(loop,exp) $ $?dp=0:err=0:u$:u$:(u$)>10 err=1 $(u$)=09460$ $[j=1̱(u$):(u$(jj))<45-ů(u$(jj))>579ů(u$(jj))=47/err=1 $%9480%:j:u$="-."err=1 $Cerr=1dp>1"type the answer as a number":9460$ $=ans=(u$):(exp-ans)>0.005y# ="No, the answer is ";exp $$(ans-exp)0.005y# =9720% $return $ % %$(u$(jj))=46.dp=dp+1 % ,j>1Ư(u$(jj))=45-err=1 %  %k9800H&:d1=r(1)/10 +r(2)/100d+r(3)/1000:dec=d1:int=1000*dec %& %A"See if you understand this by trying the following examples" % 9800H& % %"True or false ?" %a$ %a$ %a$"t"a$"f"9650% % %n:n;"/";:d:d: % 9630% %h"No. Don't add the numbers together. It's just the second number, so the answer is ";r(2) % %K"No, its the second number, not the first, so the answer is ";r(2) % %%9720%+((*9 )+1): % "Good": % "Correct": %"Right again": %"OK": %"That's it": %"Brilliant !": %"Well done": &"Very good": &"Genius !": &HWz=110 :r(z)=(*9 )+1:z:r(1)r(2)9800H&: &R#r(1)r(2)9800H& &\ &z "trap": & &"Hit C to continue" &a$= &a$="c"9950& &a$="r"9950& & 9920& & &z=1502:z & 5  ed>crhdT$sthd$ndse$etan$ig"iF#xes(#P#xe#riangl#iagrarais%raXineaqure"qupa"NNickAcS6C6 >@@@>||XGph5 hbx4h6:6:0: physics help tape 5  G C E Tutoring  June 1984 !w(25,8):2000 r(10 ) t(5):9069m# Lscrhdr=9300T$:qsthdr=9350$:endsec=9400$:getans=9450$ fig2=8950":fig=9030F#:axes2=9000(#:eg=9040P#:axes=9100#:triangle=9150#:diagram=218:praise=9720% 5br=8100:squrec=8850":squpar=8900" 4:" PHYSICS help ph5":" Heat and energy" #:"  G C E Tutoring June 1984" 2t:"Hello, what's your name ?":n$:n$:"OK, ";n$;",":"I'll begin by telling you how touse this physics program." 4Y:"This tape covers 6 subjects which all come under the headingof heat and energy." :>:"Press the key marked C so I can type the next screenfull" <a$=:a$="c"62> = 60< >:z=1100d:z AF:"Thanks. From now on when I want you to press the C key, I'll say" D:" Hit C to continue" F4:"Here's the list of subjects on this program": H"boyle's and charles' laws molecular energy and temperaturespecific heat transmission of heat kinetic energy forms of energy" K2:"Which subject do you want to try ?":s$: Lc$=s$ N'(s$)>3s$=s$(13) Os$="boy"100d Ps$="mol"200 Qs$="kin" 300, Rs$="tra"400 Ss$="spe"500 Ts$="for"900 ^Cs$"boy"s$"mol"s$"spe"s$"tra"s$"kin"s$"for"9200# _ 70F c d f iBoyle's and Charles' l n"Boyle's and Charles' law": p"Boyle's law states that the volume of a fixed mass of gas at constant temperature is inversely proportional to its pressure :": sH"if mass and temp are constant then"::"V is proportional to 1/P": tscrhdr v"eg. A balloon contains 4dm of air at 300K when the pressure is 100 000 Pa. If the balloon is taken to an altitude where the pressure is 80 000 Pa, what is its new volume ?": x:"v2=v1 x 100 000/80 000 =v1 x 1.25 = 5 dm": zscrhdr }"Charles' law states that the volume of a fixed mass of gas at constant pressure is directlyproportional to its absolute temperature (its temperature in Kelvin)": 5"if mass and pressure are constant then :": 1"pressure is proportional to temperature": scrhdr "eg. A balloon contains 10dm of air at a pressure of 100 000 Pa when the temperature is 300K. What is the new volume at a temperature of 270K ?": ,"v2=v1 x 270/300 = 10 x 0.9 = 9dm" scrhdr qsthdr "Boyle's law states that": "1. if mass and temperature are constant, V is proportional to 1/P 2. if mass and pressure are constant, P is proportional to T 3. if mass and temperature are constant, V is proportional to P": 4exp=1:egc=3:return=152:getans "Charles' law states that ": "1. if mass and temperature are constant, V is proportional to 1/P 2. if mass and pressure are constant, P is proportional to T 3. if mass and temperature are constant, V is proportional to P": 4exp=2:egc=3:return=160:getans A"In Boyle's and charles' laws, temperature is measured in ": S"1. Celsius 2. Kelvin 3. Centigrade": 4exp=2:egc=3:return=168:getans scrhdr 2n$=c$:start=100d:return=198:endsec     mol. energy and temp.  &"Molecular energy and temperature": Բ"When the temperature of an object increases, it is because it possesses more energy internally, ie. the molecules from which it is composed have more energy.": ׹"A molecule with little energy isa slow moving one; a high energymolecule is a fast moving one. The heat energy is consequently ""stored"" as the kinetic energy of the molecules.": scrhdr qsthdr V"The kinetic energy of a moleculeis high if the temperature of the substance is": Q"1. high 2. low 3. changing": 4exp=1:egc=3:return=230:getans (scrhdr )2n$=c$:start=200:return=298*:endsec * + , . 1K.E. and momentum 4 6!"Kinetic energy and momentum": 8D"The momentum of an object is theproduct of its mass and velocity" ;":"momentum = mass x velocity": >]"Here is a table of common-place objects and the amount of momentum they posess : ": ?7:0 @" Object vel mass momentum":5:0:" car 66mph 30ms 1000kg 30000Ns bike 22mph 10ms 80kg 800Ns bottle 5ms 5kg 5Ns tossed coin 3ms 0.01kg .03Ns " A6:0 Bscrhdr EB"Kinetic energy is the energy that a moving body posesses.": H"To lift an object - eg. a rock -to a certain height requires a specific amount of energy. The amount depends on the mass of the object and the height to which it is lifted.": J"While the object is stationary it posesses POTENTIAL energy. This is translated into kinetic energy if the object is dropped." Lscrhdr OQ"Here is a table of common-place objects and the kinetic energy they have :": P0:7 R&:"object mass vel K.E. " T 5 V" car 1000kg 30ms 450 000bike 80kg 10ms 4 000bullet 0.01kg 400ms 800air-gun 0.001kg 142ms 10fly 0.0001kg 2ms 0.0002" Y0:6 \ ^W"Kinetic energy is calculated by multiplying half the mass by thesquare of velocity." _ 7 `&:"K.E. = 1/2 mass x (velocity) " a 6 cscrhdr f`"Here is an example of a calculation to find the kinetic energy of a moving object.": hw"A brick is thrown at 10ms by a demomstrator. If the brick has a mass of 4kg, what is its kinetic energy ? ": j&"K.E. = 1/2 x 4 x (10) = 200J ": mqsthdr pt"What is the kinetic energy of anobject of mass ";r(1);"kg if it is travelling at ";r(2);"ms ?": r.exp=r(1)*r(2)*r(2)/2 t'egc=3:return=375w:getans w@"More questions ? (Y or N)":b$:b$:b$="y"b$="Y"365m scrhdr 2n$=c$:start=300,:return=398:endsec     transmission of heat  "Transmission of heat": s"Heat transfers from a hotter object to a cooler object by either conduction, convection or radiation.": ""Let's take these one by one.": scrhdr "1. Conduction": "When an object is heated, any free electrons it contains will gain kinetic energy and drift tothe cooler parts of the object. Low energy electrons will then replace them.": "Materials with free electrons are good conductors of electricity eg. metals. Metals are therefore also good conductors of heat.": scrhdr "2. Convection": "When a gas or liquid is heated, it expands. This makes it less dense than its surroundings, so it rises. The heated gas or liquid is replaced by coooler gas or liquid from its surroundings.": scrhdr "The main difference between convection and conduction is that there is very litle atomic movement involved in conduction (it is almost entirely the movement of electrons), but a very large amount of atomic movement involved in convection." scrhdr "3. radiation":  "This happens independently of atomic or fre electron movement.It is the transference of heat by electromagnetic waves (infra-red radiation). Because infra-red is a transverse wave, it can travel through a vacuum. This is how the sun heats the earth." scrhdr qsthdr "Conduction is caused by ": R"1. movement of free electrons 2. air currents 3. radiation": 4exp=1:egc=3:return=455:getans "Convection is caused by": R"1. movement of free electrons 2. air currents 3. radiation": 4exp=2:egc=3:return=462:getans !"Good conductors of heat are": N"1. good electrical conductors 2. electrical insulators 3. gases": 4exp=1:egc=3:return=470:getans scrhdr 2n$=c$:start=400:return=498:endsec     specific heat  "Specific heat"::"Heat is energy, and energy is measured in Joules. It is temperature which is measured inKelvin. Do not confuse the two.": x"A small object at a very high temperature may contain less heat energy than large object ata low temperature.": "When an object is heated, its molecules speed up. The increasein temperature depends on the type of molecules, and thereforeon the substance the object is made from.": scrhdr *"heat energy = massx shc x changein T":  "shc stands for specific heat capacity. Different materials have differing values of shc. A large value means that a substance takes a great deal of heat to change its temperature. A low value means that a little heat will cause a large change in temperature.":  scrhdr  ;"eg. water 4200 J/kg K lead 150 J/kg K": "Which means that 1kg of water isabout 28 times better at being the inside of a hot water bottlethan 1kg of lead, because it holds 28 times as much heat." scrhdr "eg. A bath contains 200kg of water at a temperature of 35C. If it started at 15C, and the shc of water is 4200J/kg K, how much energy has been used to heat the water ?": y"heat energy = mass x shc x change in temperature = 200 x 4200 x 20 = 16 800 000 Joules": scrhdr qsthdr 1"An electric kettle contains ";r(1);" kg" !7"of water. It is heated from ";r(2)*3;"C" $&"to 100C. How much energy is used": &!:"I'll give you some help ..." (#"What is the temperature rise ?" +Iexp=100d-3*r(2):egc=3:return=558.:getans - .E"energy = mass x shc x temp rise"::"How much energy was used ?": 0aexp=4200h*r(1)*(100d-3*r(2)):egc=3:return=5622:getans 22"specific heat capacity is measured in ": 5O"1. kg/J/K 2. J/k 3. J/kg/K": 84exp=3:egc=3:return=570::getans : "Heat energy is measured in":  electrical -> K.E.": "eg. a light bulb": !"electrical -> heat -> light": scrhdr qsthdr ="How many forms of energy can youremember ? Type some in":  e$:e$ "more ? (Y or N)": -b$:b$:b$(11)"y"948  938 +"Here's the list you could've had :": "Kinetic energy Potential energy Heat Electromagnetic radiation chemical energy electrical energy": scrhdr 2n$=c$:start=900:return=998:endsec      N T    x z     @ B H   scalars and vectors  :"Scalars and vectors": }"Quantities such as mass, volume and length are called SCALAR quantities. Scalar quanties havesize but not direction.": z"Quantities such as velocity and acceleration have both size and direction. Thistype of quantity is called a vector.": D"The general propertyof a vector is that it has two components.": scrhdr qsthdr 1:"Which of these is a vector quantity ? " S:"1. length 2. time 3. velocity": 5exp=3:egc=3:return=1760:getans 3start=1700:return=1798:n$="vectors" endsec      vector arith. & laws  ":"Vector arithmetic and laws": ^"Vector arithmetic is very simpleand follows the laws of conventional arithmetic.": "Addition": <"Two vectors a and b add to make a vector c as follows:": ""a = 2 b = 3":" 1 4" 8i=12 :x=29:y=63?:br:x=93]:br &:"c = 2+3 = 5":" 1+4 = 5" x=101e:y=39':br  x=39':i=24:br !scrhdr $""a = 2 b = 3":" 1 4" &&:"c = 2+3 = 5":" 1+4 = 5" '9i=12 :x=29:y=151:br:x=93]:br (n:"Vector addition is commutative since it makes no difference which way round the vectors are added.": )&x=101e:y=39'+88X:br *x=39':i=24:br +"a + b = b + a = c": ."This is easy to see if you thinkof the vectors as position vectors. It makes no difference which one is taken first - the final position is the same." 0scrhdr 2"vector addition is also associative. Three vectors a, b and c add to make the same result in both of the following ways:": 54" d = a + (b + c) d = (a + b) + c" 8_:"Again, this can be easily understood if the vectors are thought of as positional." :3:"Vector subtraction is also conventional." <scrhdr ?"Vector multiplication": B/"A vector can be multiplied by a scalar:": D1" eg. a = 2 1": F:" eg. 2a = 2 x 2 = 4 2 x 1 = 2" GFi=12 :x=165:y=87W:br:x=77M:y=111o:br H(i=44,:x=85U:y=87W:br Iscrhdr Lqsthdr N/:"Is vector addition commutative ?":a$:a$ P;a$="No"a$="no""Yes it is ! Read the section again." Sa$="yes"a$="Yes"praise V(:"Is vector addition associative ?": X a$:a$ Z;a$="No"a$="no""Yes it is ! Read the section again." ]a$="yes"a$="Yes"praise b=n$="vector arithmetic":start=1800:return=1898j gendsec j k l n qvelocity triangles t v:"Velocity triangles"::"Sometimes it is necessary to know the length of a vector rather than its individual components.": x"Since the two components of a positional vector are at right angles to each other, the lengthof a vector can be calculated using Pythagoras' theorem." yscrhdr {:"For example, the length of a vector:"::" 4":" 3":::::::::"is 5. This can be seen in the triangle above." }1x=14-1:y=119w:i=12 :br ~label=0:triangle O"AB represent a the x component and BC the y component. AC is the length." scrhdr "The length of the vector can represent quantites such as speed. If an aircraft is flying at right angles to the wind its ground speed can be calculated using vectors:":  triangle q"AB represents the aircraft's airspeed, BC represents the wind velocity and AC represents the ground speed." 8,17;"air speed=150":10 ,17;"wind speed=80":12 ,17;"AC=150+80":12 +1,20;"AC=28900":14,21;"AC=170"  :::: scrhdr "Sometimes velocities will not be at right angles. In these cases Puthagorus cannot be used as the resultant triangle is not right angled." d:"The length can be calculated in these cases by drawing the triangle and measuring length." >n$="velocity triangles":start=1900l:return=1998 endsec   x$="": o=1̱x$ n=18 #w(o,n):x$(oo)+n-1,w(o,n) n o  H24,16,16,32 ,16,16,24,0 C24,8,8,4,8,8,24,0 F0,0,62>,64@,64@,64@,62>,0 E0,0,124|,2,2,2,124|,0 G0,66B,66B,66B,66B,66B,44,,0 G0,44,,66B,66B,66B,66B,66B,0  G0,0,60<,64@,124|,64@,60<,0 I240,8,120x,128,248,0,0,0 C0,0,0,4,126~,4,0,0 I248,136,136,136,0,0,0,0 C4,4,228,4,0,0,0,0 G240,8,240,8,240,0,0,0 G28,20,16,16,8,8,40(,568  E4,68D,228,68D,0,0,0,0 "G16,16,16,0,0,480,72H,480 %E12 ,18,18,12 ,0,0,0,0 (E7,4,4,8,8,144,80P,32 *G4,8,16,16,16,32 ,32 ,32 ,G32 ,32 ,32 ,16,16,16,8,4 /C32 ,16,8,8,8,4,4,4 2C4,4,4,8,8,8,16,32 4 )::(40(*3.14159Iρ/180)  z=31000 %v=((z^2-(z-1)^2)) u=v^0.5 C((u)-(u+0.5))<0.01z# =z;":";z-1;":";v^0.5 z  z=07 z:7-z 7x=13:"" c=110 :c x z 0::" G C E TUTORING"::" Orders"  @"A geometric figure can be rotated by multiplying the individual coordinates by one ofthree different transformation matrices, depending on whether rotation through 90,180 or 270 is required.": B&"For a 90 rotation, multiply by:": E" 0 -1":" 1 0": H,"A 90 rotation is shoen in the diagram." I J:"The coordinates of the corners of the triangle are:": L&" 2 2 3":" 2 1 1": MM"which when multiplied by the matrix for a 90 rotation become:": N?" 0 -1 2 0-3 -3 1 0 3 2+0 2": O?" 0 -1 2 0-1 -1 1 0 1 2+0 2": P=" 0 -1 3 0-1 -1 1 0 1 3-0 3" R scrhdr:  Gx,y:0,16,-/3:x+i,y:0,16,/3: "There is a special matrix calledthe UNIT or identity matrix. If another matrix is multiplied by it there is no effect, rather like multiplying a number by 1 in ordinary arithmetic." $:"This is the 2x2 unit matrix:": " 1 0":" 0 1": 'x=8:i=24:y=80P:br scrhdr  " "square + rectangle "]27,568:502,0:0,502:-502,0:0,-502 "_27,568:100d,0:0,502:-100d,0:0,-502 "$7,2;"A D F" "%15,2;"B C E" " " "square + parallelogram "]27,568:75K,0:0,502:-75K,0:0,-502 "`27,568:75K,0:25,502:-75K,0:-25,-502 "#7,3;"A E D F" "!15,3;"B C" " " #K27,568:110n,0:568,41):0,557 #f15,7;"0":15,9 ;"2":15,11 ;"4":15,12 +1;"6" #E14,6;"0":12 ,6;"2":10 ,6;"4" #K27,568:110n,0:568,41):0,557 # [568+16,568+8:0,16:8,-16:-8,0 # ^568+32 ,568+16:0,32 :16,-32 :-16,0 #\568-10 ,568+16:-16,0:16,8:0,-8 #11 ,9 ;"A" #9 ,12 ;"B" #11 ,4;"C" #& #' #( #2K27,41):110n,0:27,41):0,557 #:]17,3;"0":17,6;"2":17,9 ;"4":17,12 ;"6" #<17,15;"8" #>\16,2;"0":14,2;"2":12 ,2;"4":10 ,2;"6" #A #Fi579+x,513+y:20,20:-20,20:-20,-20:20,-20: #Hc72H+x,568+y:0,30:-30,0:0,-30:30,0: #P'"Here is an example of ";n$ #R #Z #\ #_noises #b #d-z=120:0.01z# =,-24:z #f #h #i&z=15:0.3,t(z):z #l #mz=15:t(z):z: #n*7,9 ,5,-7,0 # # # #axes # #_30,90Z:210,0:30,90Z:0,557:0,-110n #10 ,2;"0" #f11 ,9 ;"90":11 ,15;"180":11 ,22;"270":11 ,29;"360" #atype=09124# #atype=19130# #.4,2;"1":16,1;"-1" #07,1;".5":13 ,0;"-.5" # #.7,2;"1":13 ,1;"-1" #.4,2;"2":16,1;"-2" # # # #draw triangle # #N30,60<:100d,0:0,60<:-100d,-60< #label=09175# #15,6;"adjacent" # 8,1;"hypoteneuse" #11 ,18;"opposite" #6123{,60<:0,7:7,0 #H41),60<:0,2:-3,2:-2,0 #14,2;"A" #14,17;"B" #6,17;"C" #::::::::: # # #)::9200#+((*6)+1): #"Berk ! What's ";c$;" ?": #'"Wally ! ";c$;" isn't on the tape.": ##"Moron ! Try spelling straight": #"sorry, ";n$;" ? ": #"Are you tired, ";n$;" ?": #"Don't wind me up, ";n$: $T $V scrhdr() $Y $\9900&:: $ $ qsthdr() $ $'9600%:9900&:egc=0: $ $ $endsec(start,n$) $ $7"That finishes: ":n$:"Hit r to repeat this section" $ 9900& $a$="r"start $return $ $ $getans(loop,exp) $ $?dp=0:err=0:u$:u$:(u$)>10 err=1 $(u$)=09460$ $[j=1̱(u$):(u$(jj))<45-ů(u$(jj))>579ů(u$(jj))=47/err=1 $%9480%:j:u$="-."err=1 $Cerr=1dp>1"type the answer as a number":9460$ $=ans=(u$):(exp-ans)>0.005y# ="No, the answer is ";exp $$(ans-exp)0.005y# =9720% $return $ % %$(u$(jj))=46.dp=dp+1 % ,j>1Ư(u$(jj))=45-err=1 %  %k9800H&:d1=r(1)/10 +r(2)/100d+r(3)/1000:dec=d1:int=1000*dec %& %A"See if you understand this by trying the following examples" % 9800H& % %"True or false ?" %a$ %a$ %a$"t"a$"f"9650% % %n:n;"/";:d:d: % 9630% %h"No. Don't add the numbers together. It's just the second number, so the answer is ";r(2) % %K"No, its the second number, not the first, so the answer is ";r(2) % %%9720%+((*9 )+1): % "Good": % "Correct": %"Right again": %"OK": %"That's it": %"Brilliant !": %"Well done": &"Very good": &"Genius !": &HWz=110 :r(z)=(*9 )+1:z:r(1)r(2)9800H&: &R#r(1)r(2)9800H& &\ &z "trap": & &"Hit C to continue" &a$= &a$="c"9950& &a$="r"9950& & 9920& & &z=1502:z & ed>crhdT$sthd$ndse$etan$ig"iF#xes(#P#xe#riangl#iagrarais%qure"qupa"SboyCboygxeturr$nU16tar,B5  NNickAc >@@@>||BBBBB,,BBBBB<@|@<x~(8Xph6 ~{xQ~6:6:0: physics help tape 6  G C E Tutoring  June 1984 !w(25,8):2000 r(10 ) t(5):9069m# Lscrhdr=9300T$:qsthdr=9350$:endsec=9400$:getans=9450$ fig2=8950":fig=9030F#:axes2=9000(#:eg=9040P#:axes=9100#:triangle=9150#:diagram=218:praise=9720% electroscope=7400:parallel=7350:inc=0:triode=7700:diode=7600:series=7300:link=7250R:wiring=7000X:bulb=7050:resistor=7100:meter=7150:battery=7200  5br=8100:squrec=8850":squpar=8900" 2:" PHYSICS help ph6":" Electronics" #:"  G C E Tutoring June 1984" 2t:"Hello, what's your name ?":n$:n$:"OK, ";n$;",":"I'll begin by telling you how touse this physics program." 4u:"This tape covers 7 subjects which all come under the headingof electricity, electronics and electrostatics." :>:"Press the key marked C so I can type the next screenfull" <a$=:a$="c"62> = 60< >:z=1100d:z AF:"Thanks. From now on when I want you to press the C key, I'll say" D:" Hit C to continue" F4:"Here's the list of subjects on this program": H"circuits ohm's law ammeters and voltmeters series and parallel cathode ray oscilloscope electronics static electricity" K2:"Which subject do you want to try ?":s$: Lc$=s$ N'(s$)>3s$=s$(13) Os$="cir"100d Ps$="ohm"200 Qs$="ser" 300, Rs$="amm"400 Ss$="cat"500 Ts$="ele"600X Us$="sta"900 ^Cs$"cir"s$"Ohm"s$"ser"s$"amm"s$"cat"s$"ele"9200# _ 70F c d f i circuits l n"Circuits": p~"An electric circuit allows the flow of current from its source and back again. This is why it is called a ""circuit"".": rQ"A circuit with a bulb and battery is shown on the next page.":scrhdr swiring:battery:link:bulb tscrhdr v"Circuits are drawn ""schematically"". This means thatsymbols are used for components in the circuit instead of pictures. The circuit on the previous page is drawn with these symbols.": xD"If the two terminals (+ve and -ve) of a battery are connected together without going through a bulb or any other component, a short circuit is formed. This draws a very large current from the battery. In the case of mains electricity the wire wouldbecome very hot due to the largecurrent, and might catch fire.": zscrhdr 2n$=c$:start=100d:return=198:endsec     Ohm's law  "Ohm's law": ԗ"The flow of current around a circuit is impeded by the resistance of conductors in its path. This resistance is measured in ohms.": "The higher the voltage pushing the current through a circuit, the greater the current that canflow. This is analogous to a plumbing system with narrow tubes - the greater the water pressure, the larger the flow ofwater.": scrhdr u"Voltage, current and resistance are connected by a relationship known as Ohm's law. The equations are :": "V=IR R=V/I I=V/R": N"An easy way of remembering theseformulae is by learning this diagram:": scrhdr:7550~ scrhdr `"Place your finger over the unknown quantity, and the equation required is left.": 2scrhdr:7550~:" V=IR I=V/R R=V/I" scrhdr e"eg. what current flows through a resistance of 15 ohms if the battery voltage is 3v ?": L"I=V/R =3/15 =0.2A": scrhdr qsthdr "Ohm's law states that :": T"1. V=I/R 2. V=R/I 3. V=IR ?": 4exp=3:egc=3:return=252:getans "What current flows through a resistance of ";r(1)*10 ;" Ohms if the":"voltage across it is ";r(2);" volts ?": &exp=r(2)/(r(1)*10 ) 'egc=3:return=260:getans )2n$=c$:start=200:return=298*:endsec * + . 1series and parallel 4 6"Series and parallel": 8"Two bulbs can be wired in two different ways. If they are wired one after the other, it iscalled SERIES. This is shown below:": ;'scrhdr:wiring:battery:link:series <scrhdr >"As there is 12v across both bulbs, and the bulbs have the same resistance as each other, half the voltage is dropped across one bulb, and half acrossthe other. The current is therefore 1A.": ?scrhdr @o"The alternative wiring arrangement is to have the bulbsside by side. This is known as parallel.": B)scrhdr:wiring:battery:bulb:parallel Clink:scrhdr E^"12v is across both bulbs. The current through each is 1A, so the total current is 2A.": Fscrhdr H?"The different wiring arrangements have theit own advantages and disadvantages. An example of series wiring is Xmas tree lights. Each bulb is 12v, but 20 in series will run at 12v x 20 = 240v, which is mains voltage. Unfortunately, ifone blows, all the lights go outas the circuit is broken.": J"A parallel wiring arrangement has the advantage that if one bulb blows, the others stay on. House hold lighting is wired this way.": Kscrhdr L"Resistors in series add:": O"total R = R1 + R2": R2"Resistors in parallel are more complicated:": T "total R = 1/( 1/R1 + 1/R2)": ^qsthdr `f"Two bulbs designed for American mains (110v) are to be run off 220v. How should they be wired ?": cu"1. series 2. parallel 3. one in series and one in parallel ?": f4exp=1:egc=3:return=360h:getans h"If a resistor of ";r(1);" ohms ":"and another of ";r(2);" ohms":"are wired in series, what is the total resistance ?": jBexp=r(1)+r(2):egc=3:return=365m:getans m"If a resistor of ";r(1);" ohms ":"and another of ";r(2);" ohms ":"are wired in parallel, what is the total resistance ?": p\exp=1/(1/r(1)+1/r(2)):egc=3:return=370r:getans 2n$=c$:start=300,:return=398:endsec     ammeters and voltmeters  "Ammeters and voltmeters": "An ammeter is a device which measures the current flow through a circuit. As it measures the flow, a break must be made in the circuit, and the ammeter connected in this break.": .scrhdr:battery:wiring:t$="A":meter:bulb scrhdr  "A voltmeter is a device which measures the voltage ACROSS a device in a circuit. Because voltage is not analogous with flow, it DOES NOT measure the voltage through a device. What flows through a device is current, which is measured in amps.": scrhdr "An ammeter can be used as a voltmeter by using the principles involved in Ohm's law. If a resistor is connected in series with the ammeter, the current flowing through it is proportional to the voltage pushing it.": "eg. If an ammeter that reads 0 to 1A is connected in series with a 10 ohm resistor, 10 volts will be required to cause a flow of 1A, and therefore make a full scale reading.": scrhdr "eg. An ammeter which reads 0 to 1mA (0.001A) is required to read 0 to 300v. What resistor is needed in series": c"V=300v I=0.001 R=V/I =300/0.001 =300 000 ohms": scrhdr qsthdr "An ammeter that reads 0 to ";r(1);" mA is required to read 0 to ";r(2);" volts What resistor needs to be":"placed in series ?": Kexp=10 *r(2)/r(1):egc=3:return=440:getans 2n$=c$:start=400:return=498:endsec     CRO  "Cathode ray tube": "A cathode ray tube is an electronic instrument which produces a graph of voltage against time on the equivalent of a small TV screen.": &"The picture is produced on a cathode ray tube. This is a device which has a phosphorescent screen at one endand an electron gun at the otherwhich causes the screen to fluoresce. The graph is producedby continuously moving the electron beam across the screen.": scrhdr "The beam is moved by applying a high voltage to flat electrodes called plates. The plates deflect the beam horizontally or vertically by attracting or repelling it.":  scrhdr  "The graph is produced by scanning the beam across the screen. This is achieved by applying a sawtooth waveform to the X plates,which move the beam horizontally.": scrhdr y"This tracks the beam across the screen, and then very quickly returns to the left hand side for the next sweep.": v"The voltage being measured is amplified and then applied to the Y plates, which move the beam vertically.": scrhdr qsthdr Z"What does a cathode ray tube accelerate that strikes the fluorescent screen ?": U"1. electrons 2. alpha particles 3. cathodes ?": 4exp=1:egc=3:return=545!:getans !U"Which electrode produces vertical movement of the electron beam ?": $N"1. Y plates 2. X plates 3. anode": &4exp=1:egc=3:return=552(:getans U2n$=c$:start=500:return=598V:endsec V W X Z ] electronics ` b"Electronics": d"Electronics differs from what has been covered so far in that it concerns active devices. An active device is one which can in some way control the flow of current, rather than merely passively impede it.": g"The first active device to be invented was the thermionic diode. A diode allows the flow of current in only one directionIt can therefore convert AC to DC.": hscrhdr je"A thermionic diode consists of a filament, a cathode and an anode. The filament is like the filament of a bulb, and heats the the cathode to such a high temperature that some electrons are liberated. These are attracted by the anode, as long as it is positive. If the anode is -ve, the electrons are repelled, and no current flows.": lscrhdr:diode mscrhdr n"By applying a voltage to a third electrode added to the diode, it is possible to producea large change in the current flowing through it. This new device is called a triode, and permits the amplification of small signals.": qscrhdr:triode rscrhdr t"The modern version of a triode is the transistor. This is a piece of semiconducting materialwith a conductivity which is controllable by applying a small current to a 3rd electrode": wscrhdr x"A radio makes use of diodes and transistors, as well as many other passive components. It consists of three main stages": {R:"1. tuned circuit 2. detector 3. amplifier" |scrhdr ~F"The tuned circuit selectively picks up one radio signal from those receivable, so that it is not confused with the others. The detector demodulates the signal so that the audio is separated form the carrier wave (radio frequency). The signal isvery weak, and is amplified before going to the loudspeaker.": scrhdr scrhdr  950 qsthdr "Charge is measured in ": N"1. Coulombs 2. Amps 3. Volts": 4exp=1:egc=3:return=660:getans |"What is the charge in capacitor of ";10 ^r(1);" picofarads at a voltage of ";10 ^r(2);" volts ?": Vexp=10 ^(r(1)+r(2)-12 ):egc=3:return=665:getans 2n$=c$:start=900:return=998:endsec     18,0  17,9 ;"Cathode"   " ( z;start=600X:return=898:n$="matrix arithmetic" endsec     electrostatics  "Electrostatics": "So far, current electricity has been described. It involves the flow of current through a circuit. Static electricity is the accumulation of charge on anobject:": scrhdr "Static charges can be built up by friction between insulators. Very high voltages can be produced, but the actual charge is very small.": "Static charges are detected with an electroscope. This is a device which relies on the principle that like charges repel:": scrhdr scrhdr:electroscope:scrhdr M"The greater the angle of deflection, the greater the charge.": scrhdr v"Very high voltages can be produced by a Van der Graaf generator. This consists of a vertical moving insulating belt carrying charge to a large hollow conducting sphere at the top of the generator. Charge is sprayed on at the base of the column, and is picked up by a comb-like electrode in the sphere. Voltages of 1 000 000v can be produced.": scrhdr "Charge is measured in Coulombs, and the ability of a capacitor to store it is measured in Farads. The farad is a very big unit, so the picofarad (10^-12F)is often used instead": ""Charge = capacitance x voltage"   650 qsthdr %"A diode allows current to pass:": ^"1. Both ways 2. one way 3. towards the cathode ?": 4exp=2:egc=3:return=960:getans "A triode :": V"1. amplifies signals 2. is equivalent to a transistor3. both 1. and 2.": 4exp=3:egc=3:return=968:getans "A carrier wave is": ]"1. audio frequency 2. radio frequency 3. carried by the sound": 4exp=2:egc=3:return=978:getans 2n$=c$:start=600X:return=698:endsec      N T    x z     @ B H   scalars and vectors  :"Scalars and vectors": }"Quantities such as mass, volume and length are called SCALAR quantities. Scalar quanties havesize but not direction.": z"Quantities such as velocity and acceleration have both size and direction. Thistype of quantity is called a vector.": D"The general propertyof a vector is that it has two components.": scrhdr qsthdr 1:"Which of these is a vector quantity ? " S:"1. length 2. time 3. velocity": 5exp=3:egc=3:return=1760:getans 3start=1700:return=1798:n$="vectors" endsec      vector arith. & laws  ":"Vector arithmetic and laws": ^"Vector arithmetic is very simpleand follows the laws of conventional arithmetic.": "Addition": <"Two vectors a and b add to make a vector c as follows:": ""a = 2 b = 3":" 1 4" 8i=12 :x=29:y=63?:br:x=93]:br &:"c = 2+3 = 5":" 1+4 = 5" x=101e:y=39':br  x=39':i=24:br !scrhdr $""a = 2 b = 3":" 1 4" &&:"c = 2+3 = 5":" 1+4 = 5" '9i=12 :x=29:y=151:br:x=93]:br (n:"Vector addition is commutative since it makes no difference which way round the vectors are added.": )&x=101e:y=39'+88X:br *x=39':i=24:br +"a + b = b + a = c": ."This is easy to see if you thinkof the vectors as position vectors. It makes no difference which one is taken first - the final position is the same." 0scrhdr 2"vector addition is also associative. Three vectors a, b and c add to make the same result in both of the following ways:": 54" d = a + (b + c) d = (a + b) + c" 8_:"Again, this can be easily understood if the vectors are thought of as positional." :3:"Vector subtraction is also conventional." <scrhdr ?"Vector multiplication": B/"A vector can be multiplied by a scalar:": D1" eg. a = 2 1": F:" eg. 2a = 2 x 2 = 4 2 x 1 = 2" GFi=12 :x=165:y=87W:br:x=77M:y=111o:br H(i=44,:x=85U:y=87W:br Iscrhdr Lqsthdr N/:"Is vector addition commutative ?":a$:a$ P;a$="No"a$="no""Yes it is ! Read the section again." Sa$="yes"a$="Yes"praise V(:"Is vector addition associative ?": X a$:a$ Z;a$="No"a$="no""Yes it is ! Read the section again." ]a$="yes"a$="Yes"praise b=n$="vector arithmetic":start=1800:return=1898j gendsec j k l n qvelocity triangles t v:"Velocity triangles"::"Sometimes it is necessary to know the length of a vector rather than its individual components.": x"Since the two components of a positional vector are at right angles to each other, the lengthof a vector can be calculated using Pythagoras' theorem." yscrhdr {:"For example, the length of a vector:"::" 4":" 3":::::::::"is 5. This can be seen in the triangle above." }1x=14-1:y=119w:i=12 :br ~label=0:triangle O"AB represent a the x component and BC the y component. AC is the length." scrhdr "The length of the vector can represent quantites such as speed. If an aircraft is flying at right angles to the wind its ground speed can be calculated using vectors:":  triangle q"AB represents the aircraft's airspeed, BC represents the wind velocity and AC represents the ground speed." 8,17;"air speed=150":10 ,17;"wind speed=80":12 ,17;"AC=150+80":12 +1,20;"AC=28900":14,21;"AC=170"  :::: scrhdr "Sometimes velocities will not be at right angles. In these cases Puthagorus cannot be used as the resultant triangle is not right angled." d:"The length can be calculated in these cases by drawing the triangle and measuring length." >n$="velocity triangles":start=1900l:return=1998 endsec   x$="": o=1̱x$ n=18 #w(o,n):x$(oo)+n-1,w(o,n) n o  H24,16,16,32 ,16,16,24,0 C24,8,8,4,8,8,24,0 F0,0,62>,64@,64@,64@,62>,0 E0,0,124|,2,2,2,124|,0 G0,66B,66B,66B,66B,66B,44,,0 G0,44,,66B,66B,66B,66B,66B,0  G0,0,60<,64@,124|,64@,60<,0 I240,8,120x,128,248,0,0,0 C0,0,0,4,126~,4,0,0 I248,136,136,136,0,0,0,0 C4,4,228,4,0,0,0,0 G240,8,240,8,240,0,0,0 G28,20,16,16,8,8,40(,568  E4,68D,228,68D,0,0,0,0 "G16,16,16,0,0,480,72H,480 %E12 ,18,18,12 ,0,0,0,0 (E7,4,4,8,8,144,80P,32 *G4,8,16,16,16,32 ,32 ,32 ,G32 ,32 ,32 ,16,16,16,8,4 /C32 ,16,8,8,8,4,4,4 2C4,4,4,8,8,8,16,32 4 )::(40(*3.14159Iρ/180)  z=31000 %v=((z^2-(z-1)^2)) u=v^0.5 C((u)-(u+0.5))<0.01z# =z;":";z-1;":";v^0.5 z  z=07 z:7-z 7x=13:"" c=110 :c x z 0::" G C E TUTORING"::" Orders"  z=025 x=14 code=(c$(xx))+z  code>"z"code=code-26 code; x::z ( X Z ]wiring ` b502,110n:0,40(:40(,0:130,150:40(,0:0,-40(:170,70F:0,-40(:-120x,0:0,40( g   bulb  170+inc,110n z=15 0,-8, z !170+inc,90Z,20     resistor  170,110n z=14 %5,-5:-5,-5 z     meter(type)  110n,150,20 3,14-1;t$ 17,0;" "    " % battery ( *502,110n ,0,-18 /8-10 ,0:20,0:-10 ,0 2502,83S 48-15,0:30,0:-15,0 60,-18 P R T Wlink Z \&90Z,150:40(,0 |   bulbs in series  '170,96`:0,-12 170,103g,7 170,77M,7 170,111o x=14 & 2,-2:-2,-2 x 170,111o-26 x=14 & 2,-2:-2,-2 x     parallel  inc=45-:bulb 9170+inc,70F:0,-40(:-inc,0 9170+inc,110n:0,40(:-inc,0  inc=0    electroscope  502,502 $502,0:0,502 &-502,0:0,-502 75K,115s 0,-45- /75K,115s-37%:4,-7 &60<,115s:30,0  V$7000X:7050:7150 X'170,150:0,40( | ~  triangle VIR  80P,80P <100d,0:-502,86V:-502,-86V 130,80P 70,43+:-25,0:502,0 9 ,12 +1;"I" '9 ,12 +1+5;"R" 4,12 +4;"V" 15,0;" "    diode  502,502 '0,80P:30,0,- 0,-80P -30,0,- 65A,145 %0,-10 :-7,0 14,0 524,43+ x=14 6,0,- x 524,43+ 0,-10 524+24,43+ 0,-10 4,11 ;"Anode" 17,11 ;"Cathode"    triode  "10 ,6;"- - - Grid"  diode D F H Kradio N P502,80P RJ502,0:0,502:-502,0:0,-502 U110n,80P XJ502,0:0,502:-502,0:0,-502 Z170,80P \J502,0:0,502:-502,0:0,-502 v @"A geometric figure can be rotated by multiplying the individual coordinates by one ofthree different transformation matrices, depending on whether rotation through 90,180 or 270 is required.": B&"For a 90 rotation, multiply by:": E" 0 -1":" 1 0": H,"A 90 rotation is shoen in the diagram." I J:"The coordinates of the corners of the triangle are:": L&" 2 2 3":" 2 1 1": MM"which when multiplied by the matrix for a 90 rotation become:": N?" 0 -1 2 0-3 -3 1 0 3 2+0 2": O?" 0 -1 2 0-1 -1 1 0 1 2+0 2": P=" 0 -1 3 0-1 -1 1 0 1 3-0 3" R scrhdr:  Gx,y:0,16,-/3:x+i,y:0,16,/3: "There is a special matrix calledthe UNIT or identity matrix. If another matrix is multiplied by it there is no effect, rather like multiplying a number by 1 in ordinary arithmetic." $:"This is the 2x2 unit matrix:": " 1 0":" 0 1": 'x=8:i=24:y=80P:br scrhdr  " "square + rectangle "]27,568:502,0:0,502:-502,0:0,-502 "_27,568:100d,0:0,502:-100d,0:0,-502 "$7,2;"A D F" "%15,2;"B C E" " " "square + parallelogram "]27,568:75K,0:0,502:-75K,0:0,-502 "`27,568:75K,0:25,502:-75K,0:-25,-502 "#7,3;"A E D F" "!15,3;"B C" " " #K27,568:110n,0:568,41):0,557 #f15,7;"0":15,9 ;"2":15,11 ;"4":15,12 +1;"6" #E14,6;"0":12 ,6;"2":10 ,6;"4" #K27,568:110n,0:568,41):0,557 # [568+16,568+8:0,16:8,-16:-8,0 # ^568+32 ,568+16:0,32 :16,-32 :-16,0 #\568-10 ,568+16:-16,0:16,8:0,-8 #11 ,9 ;"A" #9 ,12 ;"B" #11 ,4;"C" #& #' #( #2K27,41):110n,0:27,41):0,557 #:]17,3;"0":17,6;"2":17,9 ;"4":17,12 ;"6" #<17,15;"8" #>\16,2;"0":14,2;"2":12 ,2;"4":10 ,2;"6" #A #Fi579+x,513+y:20,20:-20,20:-20,-20:20,-20: #Hc72H+x,568+y:0,30:-30,0:0,-30:30,0: #P'"Here is an example of ";n$ #R #Z #\ #_noises #b #d-z=120:0.01z# =,-24:z #f #h #i&z=15:0.3,t(z):z #l #mz=15:t(z):z: #n*7,9 ,5,-7,0 # # # #axes # #_30,90Z:210,0:30,90Z:0,557:0,-110n #10 ,2;"0" #f11 ,9 ;"90":11 ,15;"180":11 ,22;"270":11 ,29;"360" #atype=09124# #atype=19130# #.4,2;"1":16,1;"-1" #07,1;".5":13 ,0;"-.5" # #.7,2;"1":13 ,1;"-1" #.4,2;"2":16,1;"-2" # # # #draw triangle # #N30,60<:100d,0:0,60<:-100d,-60< #label=09175# #15,6;"adjacent" # 8,1;"hypoteneuse" #11 ,18;"opposite" #6123{,60<:0,7:7,0 #H41),60<:0,2:-3,2:-2,0 #14,2;"A" #14,17;"B" #6,17;"C" #::::::::: # # # #"Berk ! What's ";c$;" ?": #'"Wally ! ";c$;" isn't on the tape.": ##"Moron ! Try spelling straight": #"sorry, ";n$;" ? ": #"Are you tired, ";n$;" ?": #"Don't wind me up, ";n$: $T $V scrhdr() $Y $\9900&:: $ $ qsthdr() $ $'9600%:9900&:egc=0: $ $ $endsec(start,n$) $ $7"That finishes: ":n$:"Hit r to repeat this section" $ 9900& $a$="r"start $return $ $ $getans(loop,exp) $ $?dp=0:err=0:u$:u$:(u$)>10 err=1 $(u$)=09460$ $[j=1̱(u$):(u$(jj))<45-ů(u$(jj))>579ů(u$(jj))=47/err=1 $%9480%:j:u$="-."err=1 $Cerr=1dp>1"type the answer as a number":9460$ $=ans=(u$):(exp-ans)>0.005y# ="No, the answer is ";exp $$(ans-exp)0.005y# =9720% $return $ % %$(u$(jj))=46.dp=dp+1 % ,j>1Ư(u$(jj))=45-err=1 %  %k9800H&:d1=r(1)/10 +r(2)/100d+r(3)/1000:dec=d1:int=1000*dec %& %A"See if you understand this by trying the following examples" % 9800H& % %"True or false ?" %a$ %a$ %a$"t"a$"f"9650% % %n:n;"/";:d:d: % 9630% %h"No. Don't add the numbers together. It's just the second number, so the answer is ";r(2) % %K"No, its the second number, not the first, so the answer is ";r(2) % %%9720%+((*9 )+1): % "Good": % "Correct": %"Right again": %"OK": %"That's it": %"Brilliant !": %"Well done": &"Very good": &"Genius !": &HWz=110 :r(z)=(*9 )+1:z:r(1)r(2)9800H&: &R#r(1)r(2)9800H& &\ &z "trap": & &"Hit C to continue" &a$= &a$="c"9950& &a$="r"9950& & 9920& & &z=1502:z & ed>crhdT$sthd$ndse$etan$ig"iF#xes(#P#xe#riangl#iagrarais%lectroscoparallenriodioderieinRirinXulesistoeteatter qure"qupa"gxm7eturr$ntarTACstaticSstaU15  NNIckAc >@@@>||BBBBB,,BBBBB<@|@<x~Xph7 nci=n6:6: physics help tape 7  G C E Tutoring  April 1984 !w(25,8):2000 r(10 ) t(5):9069m# Lscrhdr=9300T$:qsthdr=9350$:endsec=9400$:getans=9450$ fig2=8950":fig=9030F#:axes2=9000(#:eg=9040P#:axes=9100#:triangle=9150#:diagram=218:praise=9720% 5br=8100:squrec=8850":squpar=8900" 3:" PHYSICS help ph7":" NUCLEAR PHYSICS" $:"  G C E Tutoring April 1984" 2q:"Hello. What's your name ?":n$:n$:"OK, ";n$;", I'll begin by telling you how to use this physics program" 4Y:"This tape covers 6 subjects which all come under the headingof nuclear physics." :>:"Press the key marked C so I can type the next screenfull" <a$=:a$="c"62> = 60< >:z=1100d:z AF:"Thanks. From now on when I want you to press the C key, I'll say" D:" Hit C to continue" F4:"Here's the list of subjects on this program": H"atomic structure types of radiation radioactive decay detection of radiation isotopes uses of nuclear physics" K2:"Which subject do you want to try ?":s$: Lc$=s$ N'(s$)>3s$=s$(13) Os$="ato"600X Ps$="typ"200 Qs$="rad" 300, Rs$="det"400 Ss$="iso"500 Ts$="use"900 ^Cs$"ato"s$"typ"s$"rad"s$"det"s$"iso"s$"use"9200# _ 70F c d f    types of radiation  "Types of radiation"  8"There are 3 main types of nuclear radiation:": S"1. alpha rays 2. beta rays 3. gamma rays": "Let's take them one by one." scrhdr "1. alpha rays": i"These are the least penetrating of all nuclear radiations. A piece of paper will stop alpha rays." 4"Alpha particles are fast moving helium nuclei.": <"Ranges:"::"Air: a few cm":"Metal: much less than a mm" scrhdr :"Because all the energy of alpha radiation is absorbed by even a thin piece of material, alpha rays are very IONIZING. This means that they make the atoms of the material they are absorbed by lose electrons." scrhdr "2. Beta rays": b"Beta rays are high velocity electrons. They are more penetrating than alpha rays.": B"ranges:"::"air: 1 metre metal a few cm": "Because more beta rays pass through a material without beingabsorbed, they cause less ionization than alpha rays." scrhdr "3. gamma rays": p"Gamma rays are like X-rays, but with a shorter wavelength. They are they most penetrating radiation.": D"ranges"::"air: 10 metres or more metal: 30 cm or more" :"Because gamma rays are so penetrating, very little of their energy is absorbed by any material in their path. This means that they cause little ionization." scrhdr qsthdr  1"Which is the most ionising radiation ?":  S"1. Alpha rays 2. Beta rays 3. Gamma rays": ,exp=1:egc=3:return=275 getans 1"Which is the most penetrating radiation ?": S"1. Alpha rays 2. Beta rays 3. Gamma rays": ,exp=3:egc=3:return=285 getans "Do beta rays consist of ": e"1. electrons 2. protons 3. X-rays of a short wavelength":  ,exp=1:egc=3:return=290" !getans "<n$="types of radiation":start=200:return=295' $endsec ' + , . 1radioactive decay 4 6"Radioactive decay": 8"Radioactive isotopes are unstable, and over a period of time change into other more stable forms. This process is known as decay." ;:"A radioactive isotope does not decay to a stable form in a fixed period of time. Instead, acertain proportion of it decays.This proportion is constant no matter how much of the isotope is left." >n:"The term HALF-LIFE is used to describe how long it takes for half of the isotope to have decayed." @scrhdr B"After 1 half-life, 1/2 the isotope is left. After 2 half- lives, 1/2 of 1/2 is left. After3 half-lives, 1/2 of 1/2 of 1/2 remains.": EY"Here is a table of the amount of an isotope remaining after sucessive half-lives:" H:"half-lives amount left 1 0.5 2 0.25 3 0.125 4 0.0625 5 0.03125" Jscrhdr L"Different isotopes have widely varying half-lives. Some have half-lives of minutes while others, such as Uranium 238, have half-lives of billions of years.": O"The longer an isotope takes to decay, the less radiation it produces in a fixed period of time. Consequently, an isotope with a short half-life is (weight for weight) more radioactive than one with a longhalf-life." Rscrhdr TS"The amount of an isotope left can be plotted against time to form a graph:": V{15,70F:0,60<:15,70F:100d,0:dy=-7:count=0:15,120x WNdy=dy*0.88aG:7,dy:count=count+1:count<14343W XF5,3;"(activity)":12 +1,16;"(time)": YR"The curve is called EXPONENTIAL DECAY. Notice that it is NOT a straight line." \qsthdr ^"Is a half-life :"::"1. the time taken for half of an isotope to decay 2. half the time before none of the isotope is left 3. the time taken for all the isotope to decay?": `,exp=1:egc=3:return=355c agetans c"Do isotopes decay into:": fq"1. Stable elements, often after a series of intermediate stages. 2. half-lives" h,exp=1:egc=3:return=365m jgetans m;n$="radioactive decay":start=300,:return=370r pendsec r    detection of radiation  "Detection of radiation": "Radiation can detected through its ability to ionize. Ionization frees electrons from atoms, making electrical conduction possible in what would otherwise have been an insulator eg. air." <:"There are 3 main types of radiation detectors:": _"1. The electroscope 2. The spark gap detector 3. The Geiger-Muller tube": *:"Let's go through these one by one." scrhdr ""1. The electrosocope": "If a charged electroscope is placed near a source of ionizingradiation, it discharges. This is because the air becomes ionizedby the radiation, allowing the charge to be conducted away.": xscrhdr:"This diagram shows an electroscope discharging when inthe presence of ionizing radiation.": $x=20:ch=1:6000p %x=100d:ch=0:6000p scrhdr "2. Spark-gap detectors": "If a high enough voltage is applied to two electrodes separated by an air-gap, a sparkoccurs. This spark is the flow of current, made possible by theionization of the air.": "If the voltage between the electrodes is reduced to very slightly below that required to make a spark, if anything ionizes the air, a spark will occur.": scrhdr "A 1mm gap requires a voltage of about 4000v to make a spark. Thecloser the reduced voltage is to this figure, the less ionization is required to make aspark, and so the detector is more sensitive to ionizing radiation." Ļ:::" ":"":" ":" ":" ":"":" " H12 +1,23;"Electrode":17,23;"Electrode" ?19,0;"Insulator":19,20;"Insulator" scrhdr "3. Geiger-Muller tube": $"The GM tube works in a very similar way to the spark gap detector. There are two electrodes separated by an inertgas at low pressure. The low pressure of the gas allows the GM tube to work at a lower voltage than the spark-gap detector - usually about 450v.": scrhdr ;"Instead of seeing a spark if radiation is present, the GM tube shows the presence of radiation by being placed in a circuit with a loudspeaker or a digital counter. With a loud- speaker, a click is heard every time current flows betwen the electrodes. With a counter, one more count is recorded." " (A) (B) "::"(A) is the outer electrode and (B) is the inner electrode" scrhdr  qsthdr "radiation is detected by:": s"1. Its ionizing ability 2. Its effect on electrodes 3. Its ability to charge an electroscope" 6:exp=1:egc=3:return=476:getans  P"A GM tube and a spark gap detector are similar in that they both:": q"1. Work at the same voltage 2. Are like an electroscope 3. Have two electrodes separated by a gas": ,egc=3:exp=3:return=485 getans 6"The window on a GM tube has to be very thin if:": d"1. alpha rays are to be detected2. beta rays are to be detected 3. gamma rays are to be detected" 4egc=3:exp=1:return=491:getans  =n$="detecting radiation":start=400:return=499  :endsec     isotopes  "Isotopes": "All elements exist in various forms. These forms all have the same number of protons in the nucleus (the same atomic number)but have different numbers of neutrons. These forms of the same element are called isotopes": "Some isotopes are stable, but most are unstable. The instability makes the nucleus break up or change state. This causes radiation to be released." scrhdr }"The bigger the difference between the number of protons and neutrons, the more unstable an isotope tends to be.":  "For example, the stable isotope of carbon has 6 protons and 6 neutrons. The total number is 12, and this is why this isotopeis called carbon 12.":  z"A radioactive isotope of carbon is carbon 14. It has the same number of protons (6) but 8 neutrons instead of 6." scrhdr 5"An isotope can decay in three different ways:": "1. By giving off a beta particle one of the neutrons becomes a proton. This raises the atomic number by one, while keeping the atomic weight the same.": U"eg. Carbon 14 emits a beta particle, and becomes Nitrogen 14": scrhdr "2. By losing an alpha particle, the nucleus loses 2 protons and 2 neutrons. This lowers the atomic number by 2, and the atomic weight by 4." W:"eg. Uranium 238 emits an alpha particle, and becomes Thorium 234": scrhdr `"3. By giving off a gamma ray, the number of protons and neutrons stays the same": !S"eg. Osmium 185 emits a photon of gamma rays, and stays Osmium 185." $scrhdr &qsthdr (b"If a nucleus has a large difference between the number ofprotons and neutrons, is it ": +V"1. very stable 2. unstable 3. neutral ?": .4exp=2:egc=3:return=5600:getans 0D"If a nucleus emits a beta particle, does the atomic mass": 2\"1. increase 2. decrease 3. stay the same ?": 54exp=3:egc=3:return=5688:getans 8"Gamma rays are": :"1. fast moving electrons 2. helium nuclei 3. very short wavelength electromagnetic radiation ?" <4exp=3:egc=3:return=575?:getans ?scrhdr U:n$="isotopes":start=500:return=598V:endsec V W X Z ]atomic structure ` b"Atomic structure": dX"Atoms consist of a central NUCLEUS orbited by negatively charged ELECTRONS.": g"The nucleus is composed of a variable number of protons (positively charged) and neutrons (not charged),dependingon the element.": j"The number of protons is the ATOMIC NUMBER, and the number ofNUCLEONS (the total number of protons and neutrons) is the ATOMIC MASS NUMBER.": lscrhdr n::" .":" O":" OO":" OO":" O":" ." o/0,16;".":10 ,16;"." p85,10 ;".":5,21;"."::::: q:"The diagram shows an atom of carbon 12. There are 6 protons and 6 neutrons, orbited by 6 electrons. The number of protonsis always the same as the numberof electrons.": sscrhdr tqsthdr v:"The nucleus at the centre of an atom is composed of ": x`"1. Neutrons and protons 2. Neutrons and electrons 3. Protons and electrons ?": {4egc=3:exp=1:return=638~:getans ~"The nucleus is orbited by": T"1. Protons 2. Neutrons 3. Electrons ?": 4egc=3:exp=3:return=645:getans "Protons are": V"1. Positively charged 2. Negatively charged 3. Not charged ?": 4egc=3:exp=1:return=652:getans Bn$="atomic structure":start=600X:return=655:endsec        " ( z;start=600X:return=898:n$="matrix arithmetic" endsec     uses of nuclear physics  "Uses of nuclear physics": S"Nuclear physics is used in a wide variety of everyday applications.": ?"Here's a list of the categories that the uses fall under:": "1. Power Generation 2. Medicine 3. Industrial 4. Scientific 5. Weapons":  "Let's take these one by one:" scrhdr "1. Power Generation": "Electricity is generated in a conventional nuclear reactor by using the heat at the core of the reactor. This heat is used to turn water into steam, which drives a turbine. The turbine turns a generator, which produces electricity." :"The heat at the core of a nuclear reactor is caused by theenergy released when the nuclei of the atomic fuel disintegrate.This process is called NUCLEAR FISSION." scrhdr "2. medicine": "Radioactive isotopes are used inmedicine in the treatment of cancer. Carefully calculated doses of radiation, if applied just to the tumour, can be very helpful." :"Isotopes allow very localised applicaton of radiation. When stronger radiation is needed, the can be produced using equipment like X-ray tubes or cyclotrons." scrhdr "3. Industrial uses": 0"Radioactive isotopes are a conveniently portable source of radiation. A gamma ray source, such as cobalt 60, can be used in the same way that X-rays can.In this way a sort of X-ray picture of a metal casting, for example, can be produced withoutthe need for bulky and expensiveequipment.": 6"The picture produced is called a GAMMA RADIOGRAPH" scrhdr "4. scientific uses": "Nuclear physics is applied in many branches of scientific research. A very widespread use of the principle of half-lives, for example, is in the techniqueof CARBON DATING." :"Carbon dating is a method of calculating the age of, for example, a specimen found at an archaeological dig. It works like this:": scrhdr •"Anything which was once alive, whether animal or vegetable, contains a certain amount of a radioactive isotope of carbon called carbon 14." :"During the natural decay of the object, the carbon 14 changes toa stable isotope. By knowing howmuch carbon 14 was present to start with, how much is left andthe half-life of carbon 14, the age of the object can be calculated." scrhdr "5. Nuclear weapons": "An atomic bomb works by releasing the energy in the nucleus of a special radioactivematerial. The process is called FISSION, and is an uncontrolled version of a nuclear reactor.": "Instead of the energy being released gradually, it is released all at once. This happens if a sufficient mass of the radioactive material is accumulated. This mass is calledthe CRITICAL MASS." qsthdr 7"What process occurrs inside a nuclear reactor ?": Q"1. Fusion 2. Fission 3. Half-lives" 4egc=3:exp=2:return=984:getans ُ:"A gamma radioagraph is :":"1. A special X ray machine 2. A radioactive isotope 3. A picture produced by gamma rays" 4egc=3:exp=3:return=987:getans scrhdr \"Which isotope is used for finding the age of something which was once alive :": R"1. Carbon 14 2. Carbon 12 3. Uranium 238" 4egc=3:exp=1:return=991:getans In$="uses of nuclear physics":start=900:return=992:endsec      L N T    x z     @ B H |        j k l n t  x$="": o=1̱x$ n=18 #w(o,n):x$(oo)+n-1,w(o,n) n o  G0,24,60<,60<,60<,60<,24,0 E255,0,0,0,0,0,0,255 Q128,128,128,128,128,128,128,128 Q255,128,128,128,128,128,128,255 G0,66B,66B,66B,66B,66B,44,,0 G0,44,,66B,66B,66B,66B,66B,0  G0,0,60<,64@,124|,64@,60<,0 I240,8,120x,128,248,0,0,0 C0,0,0,4,126~,4,0,0 I248,136,136,136,0,0,0,0 C4,4,228,4,0,0,0,0 G240,8,240,8,240,0,0,0 G28,20,16,16,8,8,40(,568  E4,68D,228,68D,0,0,0,0 "G16,16,16,0,0,480,72H,480 %E12 ,18,18,12 ,0,0,0,0 (E7,4,4,8,8,144,80P,32 *G4,8,16,16,16,32 ,32 ,32 ,G32 ,32 ,32 ,16,16,16,8,4 /C32 ,16,8,8,8,4,4,4 2C4,4,4,8,8,8,16,32 4 )::(40(*3.14159Iρ/180)  z=31000 %v=((z^2-(z-1)^2)) u=v^0.5 C((u)-(u+0.5))<0.01z# =z;":";z-1;":";v^0.5 z  z=07 z:7-z 7x=13:"" c=110 :c x z 0::" G C E TUTORING"::" Orders"  p_15+x,502:502,0:0,502:-502,0:0,-502 rN40(+x,70F:0,502:-15,0:30,0 u4ch=140(+x,82R:10 ,-7 x4ch=040(+x,81Q:4,-10 zz=16::z  @"A geometric figure can be rotated by multiplying the individual coordinates by one ofthree different transformation matrices, depending on whether rotation through 90,180 or 270 is required.": B&"For a 90 rotation, multiply by:": E" 0 -1":" 1 0": H,"A 90 rotation is shoen in the diagram." I J:"The coordinates of the corners of the triangle are:": L&" 2 2 3":" 2 1 1": MM"which when multiplied by the matrix for a 90 rotation become:": N?" 0 -1 2 0-3 -3 1 0 3 2+0 2": O?" 0 -1 2 0-1 -1 1 0 1 2+0 2": P=" 0 -1 3 0-1 -1 1 0 1 3-0 3" R scrhdr:  Gx,y:0,16,-/3:x+i,y:0,16,/3: "There is a special matrix calledthe UNIT or identity matrix. If another matrix is multiplied by it there is no effect, rather like multiplying a number by 1 in ordinary arithmetic." $:"This is the 2x2 unit matrix:": " 1 0":" 0 1": 'x=8:i=24:y=80P:br scrhdr  " "square + rectangle "]27,568:502,0:0,502:-502,0:0,-502 "_27,568:100d,0:0,502:-100d,0:0,-502 "$7,2;"A D F" "%15,2;"B C E" " " "square + parallelogram "]27,568:75K,0:0,502:-75K,0:0,-502 "`27,568:75K,0:25,502:-75K,0:-25,-502 "#7,3;"A E D F" "!15,3;"B C" " " #K27,568:110n,0:568,41):0,557 #f15,7;"0":15,9 ;"2":15,11 ;"4":15,12 +1;"6" #E14,6;"0":12 ,6;"2":10 ,6;"4" #K27,568:110n,0:568,41):0,557 # [568+16,568+8:0,16:8,-16:-8,0 # ^568+32 ,568+16:0,32 :16,-32 :-16,0 #\568-10 ,568+16:-16,0:16,8:0,-8 #11 ,9 ;"A" #9 ,12 ;"B" #11 ,4;"C" #& #' #( #2K27,41):110n,0:27,41):0,557 #:]17,3;"0":17,6;"2":17,9 ;"4":17,12 ;"6" #<17,15;"8" #>\16,2;"0":14,2;"2":12 ,2;"4":10 ,2;"6" #A #Fi579+x,513+y:20,20:-20,20:-20,-20:20,-20: #Hc72H+x,568+y:0,30:-30,0:0,-30:30,0: #P'"Here is an example of ";n$ #R #Z #\ #_noises #b #d-z=120:0.01z# =,-24:z #f #h #i&z=15:0.3,t(z):z #l #mz=15:t(z):z: #n*7,9 ,5,-7,0 # # # #axes # #_30,90Z:210,0:30,90Z:0,557:0,-110n #10 ,2;"0" #f11 ,9 ;"90":11 ,15;"180":11 ,22;"270":11 ,29;"360" #atype=09124# #atype=19130# #.4,2;"1":16,1;"-1" #07,1;".5":13 ,0;"-.5" # #.7,2;"1":13 ,1;"-1" #.4,2;"2":16,1;"-2" # # # #draw triangle # #N30,60<:100d,0:0,60<:-100d,-60< #label=09175# #15,6;"adjacent" # 8,1;"hypoteneuse" #11 ,18;"opposite" #6123{,60<:0,7:7,0 #H41),60<:0,2:-3,2:-2,0 #14,2;"A" #14,17;"B" #6,17;"C" #::::::::: # # #)::9200#+((*6)+1): #"Berk ! What's ";c$;" ?": #'"Wally ! ";c$;" isn't on the tape.": ##"Moron ! Try spelling straight": #"sorry, ";n$;" ? ": #"Are you tired, ";n$;" ?": #"Don't wind me up, ";n$: $T $V scrhdr() $Y $\9900&:: $ $ qsthdr() $ $'9600%:9900&:egc=0: $ $ $endsec(start,n$) $ $7"That finishes: ":n$:"Hit r to repeat this section" $ 9900& $a$="r"start $return $ $ $getans(loop,exp) $ $?dp=0:err=0:u$:u$:(u$)>10 err=1 $(u$)=09460$ $[j=1̱(u$):(u$(jj))<45-ů(u$(jj))>579ů(u$(jj))=47/err=1 $%9480%:j:u$="-."err=1 $Cerr=1dp>1"type the answer as a number":9460$ $=ans=(u$):(exp-ans)>0.005y# ="No, the answer is ";exp $$(ans-exp)0.005y# =9720% $return $ % %$(u$(jj))=46.dp=dp+1 % ,j>1Ư(u$(jj))=45-err=1 %  %k9800H&:d1=r(1)/10 +r(2)/100d+r(3)/1000:dec=d1:int=1000*dec %& %A"See if you understand this by trying the following examples" % 9800H& % %"True or false ?" %a$ %a$ %a$"t"a$"f"9650% % %n:n;"/";:d:d: % 9630% %h"No. Don't add the numbers together. It's just the second number, so the answer is ";r(2) % %K"No, its the second number, not the first, so the answer is ";r(2) % %%9720%+((*9 )+1): % "Good": % "Correct": %"Right again": %"OK": %"That's it": %"Brilliant !": %"Well done": &"Very good": &"Genius !": &HWz=110 :r(z)=(*9 )+1:z:r(1)r(2)9800H&: &R#r(1)r(2)9800H& &\ &z "trap": & &"Hit C to continue" &a$= &a$="c"9950& &a$="r"9950& & 9920& & &z=1502:z &  m#crhdT$sthd$ndse$etan$ig"iF#xes(#P#xe#riangl#iagrarais%qure"qupa"SisoCisogxeturVr$ntarU3NNickAc<<<<BBBBB,,BBBBB<@|@<x~(8DD0H0  P    X5