At what angle with the horizontal should a ball be thrown so that the range `R` is related to the time of flight as `R = 5 T^2` ? `(Take g = 10 ms6-2)`.

Options

A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. `90^(@)`

Answer

B

Explanation

`R=5T^(2)`
`rArr(2u^(2)sin theta cos theta)/(g)=5[(2u sin theta)/(g)]^(2)`
`rArr (2u^(2) sin theta cos theta)/(g)=5xx(4u^(2)sin^(2)theta)/(g^(2))`
`rArr tan theta=1 rArr theta=45^(@)`