1. Physical Science K Warne
Ticker Tapes
Physical Science
K Warne

2. Ticker timer Pracs Compensating for friction
Ticker tape
Trolley & track
Inclined plane
Ticker timer
Ticker tape
Power source
trolley
Compensating for friction
Connect up the trolley, tape and ticker timer.
Start the timer.
Gently push the trolley down the slope.
Stop the timer when the trolley hits the end of the track.
Examine the ticker tape.
Set the angle of the slope so that with a gentle push the trolley will move down the slope with constant velocity. (………..spaced dots)

3. Constant Velocity Compensate for friction as per previous slide.
Set up apparatus as shown.
Compensate for friction as per previous slide.
Insert a fresh tape, start the timer.
Give the trolley a slight push so it moves down the slope with ……………. velocity.
Repeat steps 3 & 4 but push the trolley harder the second time.

4. Acceleration
Set up apparatus as shown.
Increase the slope until the trolley ………………. down the slope from a stationary start.
Insert a fresh tape, start the timer.
Release the trolley from the top of the slope.
Repeat steps 3 & 4 but increase the slope the second time so that the trolley accelerates FASTER.

5. Ticker Tape - calculations
SLOW Tape moves to LEFT FAST!
Analysis of the tapes Note the frequency of the timer.
Discard the beginning and end of the tapes (unevenly spaced dots).
Mark off TWO lengths or intervals.
Any uneven number of dots (even no. of spaces) will work best.
Label these intervals A - B and C - D
The distance between the intervals does not matter but you must be able to see the dots clearly.
Measure the displacement (distance from first to last dot) across EACH INTERVAL (SA-B, SC-D).
Find and label the MIDPOINTS (dot 3) of each interval A – B & C – D – x and y respectively.
Count the number of spaces between x and y.

6. Ticker Tape - calculations
SA-B
SB-C X X
Dots
A B C D x y w
Spaces
( X – Y)
Frequency of timer: 50 Hz Period of Timer = 1/FREQUENCY
If frequency = 50 Hz .: Period = 1/50 = 0.02s
Time for Interval (A-B) = spaces x period = 4 x 0.02 = 0.08s
INTERVAL
Spaces
Time (s)
Displacement (m)
Average Velocity (m/s)
Inst. Velocity at...
Change in Velocity
Acceleration (m.s-2)
A-B W
WX …
B-C X
C-D Y
XY
D-E Z
0.08 …
0.023/0.08 = … 4 …
0.023
0.050
0.100 … … … … …

7. Ticker Tape - calculations
Frequency of timer: ______ Period of Timer: _______________________
INTERVAL
Spaces
Time (s)
Displacement (m)
Average Velocity (m/s)
Inst. Velocity at...
Change in Velocity
Acceleration (m.s-2)
A-B W
WX
B-C X
C-D Y
XY
D-E Z
YZ …
Displacement (X) = Distance from first dot to last dot.
time = no of spaces x time for each space (period)
Displacement (m)
time (s)
VELOCITY =
= (m.s-1)
Change in Inst. Velocity (m/s)
time (s)
v2 - v1
t2-1
ACCELERATION = =
(m.s-2)

8. Ticker Tape - calculations
Frequency of timer: 50 Hz Period of Timer: s per space
Constant velocity
Displacement (…..) = Distance from first dot to last dot (cm) convert to (m).
time = no of spaces x period
…………….. (m)
time (s)
VELOCITY =
= (m.s-1)
acceleration V2 V1
……………(m/s)
time (s)
………
t2-1
ACCELERATION = =
(m.s-2)

9. Ticker Tape - calculations
Frequency of timer: 50 Hz Period of Timer: s per space
Constant velocity
Displacement (X) = Distance from first dot to last dot (cm) convert to (m).
time = no of spaces x period
Displacement (m)
time (s)
VELOCITY =
= (m.s-1)
acceleration V2 V1
Change in Inst. Velocity (m/s)
time (s)
v2 - v1
t2-1
ACCELERATION = =
(m.s-2)

10. Ticker Tape INFORMATION KNOWN For each interval you know the
DISTANCE COVERED
AVERAGE VELOCITY
INSTANTANEOUS VELOCITY (MIDPOINT)
TIME TAKEN
ACCELERATIONü

11. Apparatus (inc diagram) Method Results
Prac Write Up:
Aim
Apparatus (inc diagram)
Method
Results
Calculations (example one fully shown for each type of calculation done)
Formula, working and answer eg:
Av V = x/ t = 20/0.2 = 100 cm.s-1
Conclusion
Analysis