A ball is dropped from rest from a 20m high cliff at the same instant a second, identical ball is launched horizontally from the same height with a speed of 10ms−1. Ignore air resistance. What is the ratio of the speed of the launched ball to the speed of the dropped ball at the instant they hit the ground?
a) 1.4
b) 1.1
c) 1.0
d) 2.0