If the range of a gun which fires a shell with muzzle speed ν is R, then the angle of elevation of the gun is :-

Options

A. `cos^(-1)(v^2/(Rg))`
B. `cos^(-1)((Rg)/v^2)`
C. `1/2sin^(-1)(v^2/(Rg))`
D. `1/2 sin^(-1)((Rg)/v^2)`

Answer

D

Explanation

`R=(v^2 sin 2theta)/g` or `sin 2 theta =(gR)/v^2`
`therefore theta=1/2 sin^(-1) ((gR)/v^2)`