Answer
Collisions: a, b, d, e
a and b: nearly elastic
d and e: inelastic
Work Step by Step
c) is not a collision since the ball never hits anything. (All of the rest are collisions.)
The key idea with d and e is that they stick to each other following the collision, making them inelastic. a and b, however, are nearly elastic, for the objects bounce and lose almost no energy in the process.
