A ball is released from the top of a tower of height `h` meters . It takes `T` seconds to reach the ground . What is the position of the ball at `T/3` second

Options

A. `h//9` metres from the ground
B. `7h//9` metres from the ground
C. `8h//9` metres from the ground
D. `17h//18` metres from the ground

Answer

C

Explanation

`because h = ut + (1)/(2) g t^2 rArr h = (1)/(2) gT^2`
After `(T)/(3)` seconds, the position of ball,
`h' = 0 + (1)/(2) g ((T)/(3))^2 = (1)/(2) xx (g)/(9) xx T^2`
`h' = (1)/(2) xx (g)/(9) xx T^2 = (h)/(9) m` from top
`:.` Position of ball from ground `= h - (h)/(9) = (8 h)/(9) m`.