A rock is thrown at an angle such that the initial horizontal velocity is

15.0 m/s and the initial vertical velocity is 39.0 m/s. What is the greatest height the rock reaches?

A. 38.8 m

B. 46.9 m

C. 77.6 m

D. 98.2 m

Option (c) is correct.

Explanation:

initial velocity along horizontal = Vx=15 m/s

initial velocity along vertical = Viy=39 m/s

final vertical velocity at the top = 0

acceleration due to gravity=-9.8 m/s²

using kinematic equation

Vfy² = viy²+2gh

0 = (39) ²+2 (-9.8) (h)

-1521=-19.6 h

h=77.6 m