Question

What is conserved in an inelastic collision?

Answer 1

Momentum is conserved in inelastic collisions

Answer 2

There is conservation of momentum in an inelastic collision.

It is so because the total momentum of both the objects before and after collision remains the same. Although, the kinetic energy changes its energy form and doesn't remains constant.

Also momentum is a vector quantity and energy is a scalar quantity.

Even if there is change in momentum it is negligible because momentum takes time to change and there is almost no time during the collision.

It is very well known and basic law of physics that Momentum is always conserved - Law of Conservation of momentum.