A Rock Is Thrown from the Edge of the Top

Multiple Choice

A rock is thrown from the edge of the top of a 100-ft tall building at some unknown angle above the horizontal. The rock strikes the ground a horizontal distance of 160 ft from the base of the building 5.0 s after being thrown. Assume that the ground is level and that the side of the building is vertical. Determine the speed with which the rock was thrown.

A) 72 ft/s
B) 77 ft/s
C) 68 ft/s
D) 82 ft/s
E) 87 ft/s