Precautions Oil the wheels of the trolley to reduce friction. Ensure the runway is correctly sloped so that the trolley moves at constant velocity; at this point the frictional force is equal and opposite to the gravitational force.
Take care when using the metre stick to avoid parallax error. Increase the distance (s) so as to reduce the percentage error.
n f / Hz t / s v / m s1
MANDATORY EXPERIMENT 1 (PART B)
Measurement of Acceleration Method 2: Using ticker tape and timer Apparatus Ticker tape, ticker timer, trolley, sloped runway, metre stick
Procedure Increase the slope of the runway so that the trolley will roll down without being pushed. Place trolley on runway and allow it to accelerate.
Calculate the velocity of the trolley at an early stage (u) in the run and again at a later stage (v) (as per Part A).
Count the number of spaces between the middle of stage 1 and stage 2. Calculations
Calculate the time taken (t) by dividing the ‘number of spaces (n) between the middle of stage 1 and the middle of stage 2’ by the oscillating frequency (f ) of timer,
t n f
.
Calculate the acceleration of the trolley using the formula Note
a v u t
.
In practice, it is often easier to have the same number of spaces in stage 1 and stage 2.This allows us to calculate n as the number of spaces between the start of stage 1 and the start of stage 2.
