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1C30.10 - Timed Free Fall of a Ball

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​1C30.10 - Timed Free Fall of a Ball

Title1C30.10 - Timed Free Fall of a Ball

To demonstrate the time a ball takes to travel a known distance in free fall.

Assembly Instructions

The demonstration is self-contained except for the large stop clock.

Setup Time15
Operation Time
Preview Time5
Operation Instructions

​Reset the large display clock. Drop the ball through the clear PVC tube. The ball will start the timer as it passes the first photogate head, and stop the timer when it passes the second photogate head. Attached to the upper photogate head is a measuring tape whihc hangs down to the lower photogate. The lower photogate can be moved along the clear tube.


Alternative setup: Turn on the switch and hang the ball from the solenoid, then release the ball by depressing the push-button and hold down until the clock stops running. When the solenoid is released the ball drops, starting the clock automatically. The ball falls until it hits the small trip platform which turns off the clock. The timer should read approximately .64 seconds for a 2 meter drop.

Demo on DimeNo
PIRA 200Yes
Export Instructions (if different)

Using the kinematic equation: d = 1/2at2

We solve for t: t = sqrt(2d/a)

d = 2 m

a = 9.8 m/s2

t = sqrt(2*2/9.8)

t = 0.639 sec​

Category1 Mechanics
Subcategory1C - Motion in One Dimension
Keywordsuniform acceleration
Construction Information
special floor stand with dropping apparatus (solenoid, stop switch, and box)
clock - analog timer
ball bearing 1 inch
meter stick 2 meters long
timer/start/solenoid release box