Science Buddies: "Ask an Expert"

Hi -
My son & his friends are working on a 7th grade science project. Their idea - How does the length of a spring effect the distance it can propel an object. They are using small soda bottles with the ends cut off and a "pinball" mechanism in the cap with different length springs to propel a ping-pong balls. I am having a hard time finding any back up documentation to base the experiment off of. Any guidance is greatly appreciated!

Hi jessscan,

Hooke's Law describes the amount of force needed to compress a spring. Once compressed the spring has potential energy that is transformed to kinetic energy when the spring is released. This is the energy that applies to launching the pinballs in your experiment.

Science Buddies has a very good tutorial on springs with the relevant equations for force and potential energy:

https://www.sciencebuddies.org/science- ... earsprings

Also, you may find the following background information useful:

https://physics.info/springs/

http://hyperphysics.phy-astr.gsu.edu/hbase/pespr.html

https://en.wikipedia.org/wiki/Hooke%27s_law

I hope this helps. Please ask again if you have more questions.

A. Norman

Very helpful!
Thanks so much!!