A rock is thrown at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the velocity of the rock at the highest point of its trajectory?
A) 0
B) 9.8 m/s
C) It is equal to its initial horizontal velocity.
D) It is equal to its initial vertical velocity.
E) It is equal to its initial velocity.

Question

Quizplus · Accepted Answer

At the highest point of its trajectory, the vertical component of the rock's velocity is 0, but the horizontal component remains unchanged. Therefore, the velocity at the highest point is equal to the initial horizontal velocity.

A Rock Is Thrown at Some Angle Above the Horizontal