Answer to Question #22825 in Mechanics | Relativity for osilaja gbenga

Question

Conservations of linear momentum applied whether kinetic energy is conserved or not. Explain whether the conservation of kinetic energy in a given collision process atomaticaly implies that linear momentum is conserved in that process.

Answer 1

Momentum is always conserved in any closed system, however kinetic energy is not always conserved and this brings us neatly to the subject of elastic and inelastic collisions.
• An elastic collision is a collision where the both the momentum and the kinetic energy are conserved.
• In an inelastic collision the momentum is conserved but the kinetic energy is not. In fact the kinetic energy will be lower after the collision because some energy has been used in creating sound, deformation and heat. The reality is that most collisions are inelastic to some extent. However, collisions between snooker balls come quite close to being elastic collisions.