Acceleration Due to Gravity with a Ticker Timer

Use a ticker timer and tape attached to a mass to record the motion of a falling object. By measuring equal time intervals on the tape, you calculate speeds and accelerations and estimate g.

1. Set a ticker timer to 50 Hz (0.02 s per dot).
2. Thread a 1 m length of ticker tape through the timer so ~10–15 cm extends past the carbon disk.
3. Firmly tape the free end of the ticker tape to a 200g mass; ensure the tape exits the timer smoothly with minimal friction.
4. Position the timer on its side at the bench edge so the tape falls freely to the floor without rubbing.
5. Switch on the timer, hold the mass ~1 m above the floor, then release it so the tape runs through while it falls; stop the timer after the mass lands.
6. Measure 5 dot sections and use the results to calculation acceleration due to gravity.

Ticker Timer Free Fall Video - Juddy Productions:

📄 Acceleration Due To Gravity - Liacos Educational Media: https://www.liacoseducationalmedia.com/Acceleration_Due_To_Gravity_(Ticker_Timers)-Liacos_Educational_Media.pdf

• Use different masses to see that g is mass-independent (air resistance permitting).
• Increase drop height to obtain more intervals and a better line of best fit.
• Replace with a motion sensor or video tracker and compare g values.

• Keep feet clear of the falling mass; use a soft landing pad or catch safely near the floor.
• Secure the timer so it cannot fall from the bench.
• Keep fingers away from the moving tape and carbon/disc.
• If using a mains ticker timer, ensure RCD protection and teacher supervision; switch off before threading tape.
• Clear the drop zone of obstacles.

• What should the speed–time graph look like for free fall without air resistance? (A straight line through or near the origin with positive slope; slope ≈ g.)
• Why might the best-fit line not pass exactly through the origin? (Start-up friction, first few unclear dots, slack in tape, reaction timing, calibration error.)
• What do the Speed (interval) values and Acceleration values indicate about falling objects? (Speeds increase by roughly equal amounts each equal time step; acceleration is approximately constant and ≈ g.)
• If air resistance becomes significant, how would the speed–time graph change? (It would curve, slope decreases over time, approaching terminal speed.)