Question

a baseball is thrown straight up into the air and falls back down. when does the baseball have the least amount of kinetic energy? ○ when it reaches the highest point ○ as soon as it is released and right before it is caught ○ when it is held in a hand ○ it has the same amount of kinetic energy the entire time.

Explanation:

Kinetic energy \(K = \frac{1}{2}mv^{2}\), where \(m\) is mass and \(v\) is velocity. When the baseball reaches the highest point, its velocity \(v = 0\). Substituting \(v = 0\) into the kinetic - energy formula gives \(K=0\). As soon as it is released, it has some initial velocity (so non - zero kinetic energy). When held in a hand, it is not in the motion described in the problem (thrown up and coming down). And kinetic energy changes during the motion (since velocity changes).

Answer:

when it reaches the highest point