Ticker Tapes
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Ticker TapesTicker Tapes
K WarneK Warne
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ApparatusApparatus Trolley & trackTrolley & track Inclined planeInclined plane Ticker timerTicker timer Ticker tapeTicker tape Power sourcePower source
Compensating for frictionCompensating for friction
• Connect up the trolley, tape and ticker timer.Connect up the trolley, tape and ticker timer.• Start the timer.Start the timer.• Gently push the trolley down the slope.Gently push the trolley down the slope.• Stop the timer when the trolley hits the end of the track.Stop the timer when the trolley hits the end of the track.• Examine the ticker tape.Examine the ticker tape.• Set the angle of the slope so that with a Set the angle of the slope so that with a gentle pushgentle push the trolley will the trolley will
move down the slope with move down the slope with constant velocityconstant velocity. (Evenly spaced dots). (Evenly spaced dots)
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Ticker Tape - calculationsTicker Tape - calculations
Analysis of the tapes Analysis of the tapes Note the Note the frequencyfrequency of the timer. of the timer.• Discard the beginning and end of the tapes (unevenly spaced dots).Discard the beginning and end of the tapes (unevenly spaced dots).• Mark off TWO lengthslengths or or intervalsintervals..• Any Any unevenuneven number of dotsnumber of dots (even no. of spaces) will work best.• Label these intervals Label these intervals A - BA - B and and C - DC - D• The distance between the intervalsdistance between the intervals does not matter but you must be able to
see the dots clearly.• Measure the Measure the displacementdisplacement (distance from first to last dot) across EACH (distance from first to last dot) across EACH
INTERVAL (INTERVAL (SSA-BA-B, S, SC-DC-D).).• Find and label the Find and label the MIDPOINTSMIDPOINTS (dot 3) of each interval A – B & C – D – (dot 3) of each interval A – B & C – D – x x
and yand y respectively. respectively.• Count the Count the number of spacesnumber of spaces between between x and y.x and y.
... . . . . . . . . . . . . .
SLOW Tape moves to LEFT FAST!
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Ticker Tape - calculationsTicker Tape - calculations
If frequency = 50 Hz .: Period = 1/50 = 0.02s
Time for Interval (A-B) = spaces x period = 4 x 0.02 = 0.08s
1 2 3 4 Spaces
( X – Y) Frequency of timer: 50 Hz Period of Timer = 1/FREQUENCY
... . . . . . . . . . . . . . X XA B C D
SSA-BA-B SSB-CB-C
1 2 3 4 5 Dots
ww xx yy
INTERVALINTERVAL SpacesSpaces Time (s)Time (s) Displacement Displacement (m)(m)
Average Average Velocity Velocity
(m/s)(m/s)
Inst. Inst. Velocity Velocity
at...at...
Change in Change in VelocityVelocity
Time Time (s)(s)
Acceleration Acceleration (m.s(m.s-2-2))
A-BA-B WWWWXX WWXX WWXX
B-CB-C XX
C-DC-D YYXXYY XXYY XXYY
D-ED-E ZZYYZZ YYZZ YYZZ
44
44
44
0.080.08
0.080.08
0.080.08
0.0230.023
0.0500.050
0.1000.100
0.023/0.080.023/0.08
= 0.2875= 0.2875
0.05/0.080.05/0.08
= 0.625= 0.625
0.1/0.080.1/0.08
= 1.25= 1.25
0.63 – 0.290.63 – 0.29
=0.34=0.34
m.sm.s-1-1
0.080.080.33750.3375
0.080.08
= 4.22= 4.22
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Ticker Tape - calculationsTicker Tape - calculations
Displacement (S) = Distance from first dot to last dot.
VELOCITY = DisplacementDisplacement (m)
timetime (s)= (m.s-1)
ACCELERATIONACCELERATION = Inst. Velocity (m/s)
timetime (s)=
v2 - v1
tt2-12-1
timetime = no of spacesspaces x time for each spacespace (period)
Frequency of timer: ______ Period of Timer: _______________________
INTERVALINTERVAL SpacesSpaces Time Time (s)(s)
Displacement Displacement (m)(m)
Average Average Velocity Velocity
(m/s)(m/s)
Inst. Inst. Velocity Velocity
at...at...
Change Change in in
VelocityVelocity
Time Time (s)(s)
Acceleration Acceleration (m.s(m.s-2-2))
A-BA-B WW WWXX WWXX WWXX
B-CB-C XX
C-DC-D YY XXYY XXYY XXYY
D-ED-E ZZ YYZZ YYZZ YYZZ
……
(m.s-2)
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Ticker Tape GraphsTicker Tape GraphsPlot graphs on the of Plot graphs on the of DISPLACEMENT(mDISPLACEMENT(m)) against against TIMETIME(s)(s) on the same system of on the same system of
axis for axis for each tapeeach tape made. made.
Do the same for and Do the same for and VELOCITYVELOCITY (m/s) against (m/s) against TIMETIME (s) and (s) and ACCELERATIONACCELERATION against
TIMETIME . .
... . . . . . . . . . . . . . X
A B C DSSxx SSyy
ww xxt1
t2
s (m)
t (s)t1 t2 ect…
SSww
SSxx
v (m.s-1)
t (s)t1 t2 ect…
vvww
vvyy
PointPoint TimeTime(s)(s)
Disp. Disp. (m)(m)
Ins. Ins. VV (m.s(m.s-1-1))
WW
XX
yy
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Constant Velocity - calculationsConstant Velocity - calculations
LengLengthth
Time/Time/(s)(s)
Displacement Displacement /(m)/(m) VelocityVelocity
II 00 00 00
IIII 0.60.6 0.170.170.170.17
0.60.6
IIIIII 1.21.2 0.350.350.35-0.170.35-0.17
1.2-0.61.2-0.6
IVIV 1.81.8 0.520.520.52-0.350.52-0.35
1.8-1.21.8-1.2
t
v
t
s
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Acceleration - GraphsAcceleration - Graphs
t
s (m)
Displacement vs. time
t (s)x x
x
x v (m/s)
t (s)
x x x
x x
Line of best fitX
a (m/s2)
t (s)
INTERVALINTERVAL SpacesSpaces Time Time (s)(s)
Displacement Displacement (m)(m)
Average Average Velocity Velocity
(m/s)(m/s)
Inst. Inst. Velocity Velocity
at...at...
Change Change in in
VelocityVelocity
Time Time (s)(s)
Acceleration Acceleration (m.s(m.s-2-2))
A-BA-B 44 0.080.08 0.0230.0230.023/0.080.023/0.08
0.28750.2875 WWWWXX
0.625 – 0.625 – 0.28750.2875
=0.3375=0.3375
WWXX
0.080.08WWXX
0.33750.3375
0.080.08
= 4.218= 4.218B-CB-C 44 0.080.08 0.0500.0500.05/0.080.05/0.08
0.6250.625XX
constantSmooth curve
Velocity vs. time Acceleration vs. time
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VELOCITY FROM S v T GraphVELOCITY FROM S v T GraphDisplacement vs. time
s (m)
t (s)
x
x
x
x
A B C D E
Tangent (only touches curve at ONE POINT
GRADIENT
m = Change in Y
Change in X
(x1, y1)
(x2, y2)
Y2-y1
x2-x1=
x1
y1
Gradient of the displacement - time graph gives the INSTANTANEOUS VELOCITY at that point.
= velocity at. D
x2
y22
1
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Keith WarneKeith Warne