Question

1. which of the following collision types has all objects starting apart and ending as a combined mass with a shared velocity?

elastic
inelastic
explosion
unelastic

Explanation:

In an explosion, objects start apart (initially at rest or moving apart in some sense before the explosion - like internal forces causing separation) and then due to the release of energy (chemical, etc.), they come together (in the sense of forming a combined mass with a shared velocity after the explosion - considering the center - of - mass motion). In elastic and inelastic collisions (other than explosion - like scenarios), objects usually start in a more "approaching" motion (either moving towards each other or one moving towards a stationary one). Unelastic is not a standard well - defined collision type in the same context as the others.

Answer:

Explosion