Which of the following best describes the momentum of two bodies after a two-body collision if the kinetic energy of the system is conserved?

a. must be less

b. must also be conserved

c. might also be conserved

d. is doubled in value

B

Explanation:

In a two body collision where kinetic energy is conserved, this means the kinetic energy before collision is equal to the kinetic energy after collision.

when kinetic energy is conserved, momentum is also conserved.

m1u1 + m2u2 = m1v1 + m2v2

or

m1u1 + m2u2 = (m1+m2) v

The above equations are for bodies that undergoes elastic and inelastic collisions. It represents their momentum before and after collision which are equal