The expanding gases that leave the muzzle of a rifle also contribute to the recoil. A .30 caliber bullet has mass 7.20×10−3 kg a
nd a speed of 601 m/s relative to the muzzle when fired from a rifle that has mass 3.00 kg. The loosely held rifle recoils at a speed of 1.95 m/s relative to the earth. Find the momentum of the propellant gases in a coordinate system attached to the earth as they leave the muzzle of the rifle.
The chemical change occurred. Electrolysis is used by scientists to make chemical reactions that wouldnt normaly spontaniously ocur. In this case we are getting new gases from water molecul which is change in structure of elements ( we are getting new moleculs)