A stone is thrown upwards with a speed y from the top of a tower. It reaches the ground with a velocity 3v. What is the height of the tower?

A stone is thrown upwards with a speed y from the top of a tower. It r

1.	A stone is thrown upwards with a speed y from the top of a tower. It reaches the ground with a velocity 3v. What is the height of the tower?
Answer» Solution :From equation of motion v.`= u + at `….(1) `h = ut + 1/2 at^2` ` v.= av, u = v , a = + g` using EQN (1) 3V = v + gt `rArr` 3v - v = gt ` t=(2v)/(g)` substituting.t. VALUE in eqn (2) `h = v ( (2v)/(g) ) + 1/2 g ( (2v)/(g) )^2 = (2v^2)/(g) + 1/2 g ( (2v)/(g) )^2` ` h = (2v^2)/(g) + (2v^2)/(g)` ` = (4v^2)/(g) "" g = 10 ms^(-2)` ` = (4v^2)/(10) , h = (2v^2)/(5)`