A bullet is fired from horizontal ground at some angle passes through the point, where `R` is the range of the bullet. Assume point of the fire to be origin and the bullet moves in x-y plane with x-axis horizontal and y-axis vertically upwards. Then angle of projection is

Options

A. `30^@`
B. `37^@`
C. `53^@`
D. none

Answer

C

Explanation

`y=xtantheta(1-(x)/(R ))`
`implies(R )/(4)=(3R)/(4)=tantheta(1-3R)/(4R))`
`implies1=3tantheta((1)/(4))`
`impliestantheta=(3)/(4)impliestheta=53^@`