Question

A child, starting from rest at the top of a
playground slide, reaches a speed of 7.0 meters
per second at the bottom of the slide. What is
the vertical height of the slide? [Neglect
friction.]

Answer 1

m g h = (1/2) m v^2

or

h = v^2/ (2g) = 49/(2*9.81) or about 2.5 meters

Answer 2

2.5 meters