A bullet is fired horizontally and penetrates into a block of wood. The block and bullet then move together after impact. Explain the total linear momentum and total kinetic energy of the system before and after the collision

1 answer

momentum
mass bullet * u + mass wood * 0
= (mass bullet + mass wood) * v

energy
(1/2)mass bullet * u^2 + 0
= (1/2)(mass bullet+mass wood) * v^2

The Ke after will be less :) Energy was converted to heat while slowing the bullet.