# physics

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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 -

final KE=initialPE-initial KE
1/2 m v^2=mgh-1/2 m u^2

1/2m(9u^2-u^2)=mgh

solve for h.

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