Don't feel dumb. Energy transfer, forces, momentum - all these things aren't as simple as they appear and university students (including me) struggle to understand them!
First of all, we have a very important rule. It's the Law of Conservation of Energy, otherwise known as the First Law of Thermodynamics. Energy can be neither created nor destroyed, only transferred from one form to another.
If you have a ball moving through the air at, say, 3 m/s and it hits a wall and just stops and sticks there, the kinetic energy will be transferred to elastic energy as the ball stretches and deforms and squashes and changes shape, and heat energy.
A cue ball is more complicated to describe and would be best talked about in terms of momentum transfer and stuff. Basically the energy transferred from cue to ball would be the force x the distance moved in the direction of that force, and you could probably do lots of interesting calculations involving the impulse (force x time) and momentum transfers and stuff ...
I hope I'm not boring you! I seem to have sidetracked the discussion from non-contact techniques for communicating with your horse to lots of physics and mechanics. I find it fun but not everyone does xD
If you believe everything you read, better not read.
Last edited by claireauriga; 11-11-2008 at 07:06 PM.