A Rock Falls from a Vertical Cliff That Is 4

Multiple Choice

A rock falls from a vertical cliff that is 4.0 m tall and experiences no significant air resistance as it falls. At what speed will its gravitational potential energy (relative to the base of the cliff) be equal
To its kinetic energy?

A) 8.9 m/s
B) 6.3 m/s
C) 4.4 m/s
D) 13 m/s
E) 3.1 m/s