A rock is thrown vertically into the air.At the very top of its trajectory the net force on it is
A)less than its weight.
B)more than its weight.
C)equal to its weight.

Question

Quizplus · Accepted Answer

At the top of its trajectory, the rock momentarily comes to a stop before it begins to fall back down. During this brief instant, the net force acting on the rock is zero, which means that the force of gravity pulling it down is balanced by the force of the throw that sent it upward. This balance of forces corresponds to the weight of the rock, which is the force due to gravity acting on it. Therefore, the net force on the rock at the top of its trajectory is equal to its weight.

A Rock Is Thrown Vertically into the Air