# Question #bf36a

Jun 6, 2015

If the collision is non-elastic, there are some loss in energy, therefore :

• The mechanical energy and the kinetic energy aren't conserved.

However :

• The momentum ($p = m v$) and the angular momentum ($L = r m v$ or $L = I \omega$) are still conserved.

In the case of a perfectly inelastic collision, the colliding masses will stick together; for the momentum, you would have something like :

${m}_{1} {v}_{1} + {m}_{2} {v}_{2} = \left({m}_{1} + {m}_{2}\right) {v}_{3}$.