The ceiling of a hall is 40m high. For maximum horizontal distance, the angle at which the ball may be thrown with a speed of `56ms^(-1)` without hitting the ceiling of the hall is

Options

A. `25^(@)`
B. `30^(@)`
C. `45^(@)`
D. `60^(@)`

Answer

B

Explanation

`H=((u sin theta)^(2))/(2g)` `sin theta=sqrt(2gH)/(u)=sqrt(2xx9.8xx40)/(56)=(1)/(2)rArr theta=30^(@)`