Question

A passenger at the rear of a train traveling at 15 m/s relative to earth throws a baseball with a speed of 15 m/s in the direction opposite the motion of the train. what is the velocity of the baseball relative to the earth as it leaves the thrower’s hand?

Answer 1

0 m/s

Step-by-step explanation:

Let's take the direction in which the train is travelling as positive direction. Therefore:

- The velocity of the train with respect to earth is:

`v_t = +15 m/s`

- The ball is thrown with speed 15 m/s in the opposite direction, so in the frame of reference of the train, its velocity is

`v_b = -15 m/s`

Therefore, the velocity of the baseball in the earth's reference frame will be the algebraic sum of these two velocities, so:

`v_b' = v_t + v_b = +15 + (-15) = 0`