Question

A 2 kg ball is dropped from a height of 433 mm. Calculate the height (above the ground) at which KE is one third of PE.

Answer 1

Since KE + PE = constant = PEmax ,
when KE = PE/3,
(4/3)PE = PEmax
PE = (3/4)PEmax

The height must be 3/4 of 433 mm, or 325 mm