AIM: TO MEASURE VELOCITY WITH A TICKER TIMER

APPARATUS

Ticker timer, ticker tape, trolley, runway.

METHOD

Set up apparatus as in diagram.

The timer prints 50 dots per second.

Start the timer and give the trolley a gentle push.

The trolley should move along the runway with a constant velocity.
The dots on the paper tape should be equally spaced.

Ignore the first few blurred dots on the tape.

Draw a line through a dot. Count, e.g. five, more dots and draw a second line.

Measure the distance, s, between the two lines with a ruler.

Since it takes 1/50 seconds to print each dot, it took a time t = 5/50 = 0.1 seconds to print the five dots.

Thus the velocity of the trolley is given by
.

SOURCES OF ERROR

Friction may cause the trolley to decelerate.
Tilt the trolley to compensate for this.

Too much tilt may allow gravity to accelerate the trolley.

Reduce the tilt.