While the gondola is rising at a speed of 5.0 m/s, a passenger in a balloon-supported gondola throws a small ball up at a speed of 2.0 m/s relative to his body. A person who measures the ball's velocity at the instant of release will find that the ball's velocity relative to the ground at that instant is
A) 2.0 m/s, up.
B) 2.8 m/s, down.
C) 3.0 m/s, up.
D) 5.0 m/s, up.
E) 7.0 m/s, up.

Question

Quizplus · Accepted Answer

The ball's velocity relative to the ground is the sum of its velocity relative to the gondola (2.0 m/s up) and the gondola's velocity relative to the ground (5.0 m/s up), resulting in a total velocity of 7.0 m/s up.

While the Gondola Is Rising at a Speed of 5