A ball is dropped from 20 ft above ground. at what height is half it's energy kinetic and half potential?

Answer 1

Since the zero of potential can be anywhere, this problem has no unique answer. From the phrasing of the question, let's take the zero of the potential at d=0, 20ft below the drop point.

V = mgd, K = 1/2mv^2 where d is the distance above ground

K = mg(h-d), where d is the distance fallen

We want

mgd = mg(h-d) or d = h/2, a.k.a. 10ft

Answer 2

at 10 feet