Posted by pavatharani on .
a stone is thrown vertically upward with an initial velocity u from the top of tower, reaches the ground with a velocity 3u. what is the height of tower?

physics 
bobpursley,
final KE=initialPEinitial KE
1/2 m v^2=mgh1/2 m u^2
1/2m(9u^2u^2)=mgh
solve for h.