Conservation

Basics

http://www.sei.ie/Schools/Secondary_Schools/Subjects/Physics/Unit_2_-_Energy/Conservation_Principle/

Energy can neither be created nor destroyed,

it can be changed from one form to another

Newtons cradle the office toy, proof of the pudding, thanks to walter again.

That heat energy is actually kinetic energy at a particle level

http://id.mind.net/~zona/mstm/physics/mechanics/energy/heatAndTemperature/gasMoleculeMotion/gasMoleculeMotion.html