A particle of mass 1 kg is projected with all initial velocity`10 ms^(-1)` at an angle of projection `45^(@)` with the horizontal. The average torque acting on the projectile, between the time at which its is projected and the time at which it strikes the ground, about the point of projection in newton-metre is

Options

A. 25
B. 50
C. 75
D. 100

Answer

(b)

Explanation

`m=1kg`,`u=10m//s ` (given)
Average torque`=(dL)/(dt)`
`=mu^(2)cos^(2)theta`
`=1xx10^(2)xxcos^(2)45^(@)`
`=50N-m`