I read somewhere PE=KE, how? It mean we can get transfer 100% PE to KE and KE to Joule Please anyone can explain? If I throw mass of 1000kg from 50 meters height can I get energy equal to Pe=mgh = 1000*9.81*50=490500 Joule? It mean 490500Kn = 490500watt= 490.50Kw. Is it possible to to get this energy if I throw a round 1000kg sphere from 50 meters height?