Suppose M m. The small mass m (initially moving) strikes the massive body M (initially at rest). After the collision, m could never (with respect to the lab)
A) rebound at roughly the same speed.
B) glance off at roughly 90 degrees to the original direction.
C) continue approximately forward with roughly its original velocity.
D) impart to M a speed roughly equal to that originally present in m.

Question

Suppose M > m. The small mass m (initially moving) strikes the massive body M (initially at rest). After the collision, m could never (with respect to the lab)
A) rebound at roughly the same speed.
B) glance off at roughly 90 degrees to the original direction.
C) continue approximately forward with roughly its original velocity.
D) impart to M a speed roughly equal to that originally present in m.

Quizplus · Accepted Answer

Due to the conservation of momentum and the fact that M > m, it is physically impossible for the smaller mass m to impart to the larger mass M a speed roughly equal to its original speed. The momentum of the system must be conserved, and given the mass disparity, transferring all of m's initial velocity to M would violate this principle.

Suppose M > M