A Rock Is Dropped from Rest from a Height H

Multiple Choice

A rock is dropped from rest from a height h above the ground. It falls and hits the ground with a speed of 11 m/s. From what height should the rock be dropped so that its speed on hitting the ground is 22 m/s? Neglect air resistance.

A) 1.4h
B) 2.0h
C) 3.0h
D) 4.0h
E) 0.71h