# A stone is thrown vertically upwards with an initial speed u from the top of a tower, reaches the ground with a speed 3 u. The height of the tower

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A stone is thrown vertically upwards with an initial speed u from the top of a tower, reaches the ground with a speed 3 u. The height of the tower is :
A. (v^(2))/(g)
B. (2v^(2))/(g)
C. (4v^(2))/(g)
D. (8v^(2))/(g)

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According to the third equation of motion
v^(2)-u^(2)=2as given v=3v,u=v and a=g
or (3v)^(2)-v^(2)=2gs or s=(4v^(2))/(g)