An arrow is shot in air, its time of flight is 5 sec and horizontal range is 200 m. the inclination of the arrow with the horizontal is

Options

A. 12.5 m/s
B. 25 m/s
C. 31.25 m/s
D. 40 m/s

Answer

D

Explanation

`R = (u^(2) sin 2theta)/g = 200 m rArr (2u^(2) sin theta cos theta)/g = 200`
`rArr ((2u sin theta)/g) ucos theta = 200 [therefore T = (2u sin theta)/g = 5]`
`rArr u cos theta = 200/5 = 40 m//s`