1C30.10 • Measuring g: Freefall Timer

Location: Cabinet 3

Photo shows the demonstration used at the University of Texas at Austin.

---

Instructions / Notes:

• The distance between the electromagnet at the top of a ring stand and the interruptor switch is one meter.
• Do not attempt to adjust the distance between the electromagnet and the interruptor switch.
• The black "Start/Stop" button on the left releases the ball from the electromagnet at the top of the ring stand.
• To reset: push the reset button on the front panel of the timer, then push down in the inner most end on the interrupter switch (labeled #2) in the catch basket. This must be done between runs for the demonstration to function properly.
• The elapsed time should be 4.518 seconds.

Demo Staff:

• The interruptor switch - (which acts as the timer's remote cut-off switch) - is located at the bottom of the ring stand.
• The mechanical switch can get sticky after several uses, at which point the clock will run continuously after the ball drops.

Last updated on February 18, 2025