A stone is thrown upwards with a speed u from the top of a tower reaches the ground with a velocity 3 u . The height of the tower is

Options

A. `3u^2//g`
B. `4u^2 //g`
C. `6u^2 //g `
D. `9u^2//g`

Answer

B

Explanation

`v^2 = u^2 + 2gh`
`rArr (3u)^2 = (-u)^2 + 2gh rArr h = (4u^2)/(g)`