1. For which of the following situations no work is done? A) Pushing against a wall that is stationary ; B) pushing a car for a distance of 0.50 km ; C) going down a ight of stairs ; D) playing the violin ; E) slide to rest on skates. 2. Two objects of the same mess have velocities illustrated by the vectors ci- below. They collide and stick together. O | Which of the following vectors best represents the vector velocity - after the collision?' @ Ao 51 C n\\ E\\ AM B)B C)C D)D ElE