Your goal in this experiment is to determine the height of the reach of the tallest student in your group. Your tool: a stopwatch.

- Have the tallest student hold a ball in one hand,
reaching up as far as he can.
On the count of three, he should release
the ball so that it falls to the floor.
- The other students will measure the time it takes
for the ball to fall to the floor.
Write down the times.
- Repeat for a total of five trials.
- Compute the average time, and the uncertainty in
that time. Write these down.
- Use kinematics to turn the time into a distance
the ball travelled -- and its uncertainty.
Show your method clearly.

After you've found the distance using kinematics, use a meter stick to measure the actual height of the ball as it is held in the student's hand. Write down this actual height and its uncertainty.

**Are the kinematic and actual heights the same,
to within their uncertainties? **

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.