A bullet ofmass m is fired with a velocity `10m//s` at angle `theta` with horizontal. At the hightest point of its trajectory, it collsides head-on with a bob of mass `3m` suspended by a massless string of length `2//5m` and gets embedded in the bob. After th collision the string moves through an angle of `60^(@)`.
The vertical coordinate of the initial positon of the bob w.r.t. the point of firing of the bullet is

Options

A. `(9)/(4)m`
B. `(9)/(5)m`
C. `(24)/(5)m`
D. None of these

Answer

(B)

Explanation

`H_(max) = (u^(2)sin^(2) theta)/(2g) = ((100)(9//25))/(20) = (9)/(5)m`