A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's
Motion are true just before it hits the ground? (There could be more than one correct choice.)
A) Its horizontal velocity component is zero.
B) Its vertical velocity component is the same as it was just as it was launched.
C) Its horizontal velocity component is the same as it was just as it was launched.
D) Its speed is the same as it was just as it was launched.
E) Its velocity is vertical.

Question

Quizplus · Accepted Answer

C) The horizontal component of velocity remains constant throughout the motion because there are no horizontal forces acting on the rock (assuming air resistance is negligible).

A Rock Is Thrown from the Upper Edge of a Tall