1Q20.50 Faster than "g" - Hinged Stick and Ball
Concepts
Rotational motion, free fall
Overview
A ball on a hinged plank falls into a cup mounted in the plank. For the ball to fall into the cup, the cup and nearby plank segment must accelerate down faster than g.
Details
Equipment
- [1] Hinged plank with cup
- [2] C-clamp
- [1] Specially sized wooden stick
Classroom Assembly
- Clamp both ends of the lower plank to a table.
Important Notes
- Make sure nothing obstructs the removal of the stick or the follow-through motion of your hand in removing the stick.
- Doing this demo correctly requires a bit of finesse. If you move too quickly, you may jerk the top plank around and cause the ball to fall unpredictably.
Script
- Note the location of the cup when the plank is in the down position.
- Support the plank using the stick and put the ball in the small depression on the end of the plank.
- Note that the ball is now directly above where the cup will be in the down position.
- Smoothly remove the stick from under the plank.
Additional Resources
References
- PIRA 1Q20.50
Disclaimer
- Don't attempt this at home!
- SFU is not affiliated with any external sites linked here and is not responsible for their content.
Last revised
- 2023
Technicals
- Original construction: built. The cup on the plank is the top from an aerosol spray can.
Related AV
Related demos
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.