Consider a Collision Where an Object with a Known Mass

Multiple Choice

Consider a collision where an object with a known mass and known speed collides with another object at rest. The objects are free to move in three dimensions.
-(a) How many quantities suffice to completely determine the system's final state (that is, the outgoing objects' velocities and their combined change in internal energy) ?

A) Zero
B) One
C) Two
D) Three
E) Four