Starting from rest at the top, a child slides down the water slide at a swimming pool and enters the water at a final speed of 4.00 m/s. At what final speed would the child enter the water if the water slide were twice as high? Ignore friction and resistance from the air and the water lubricating the slide.

2 answers

(1/2) m v^2 = m g h
v = sqrt (2 g h)
or
v = k sqrt(h)
if you double h, you multiply v by sqrt 2
What is k?