A boy throws a cricket ball from the boundary to the wicket keeper. If the frictional force due to air $$(f_a )$$ cannot be ignored, the forces acting on the ball at the position X are represented by

A particle of mass m is projected with a velocity u making an angle $$\theta$$ with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height is

When a ball is thrown with a velocity of 50 ms$$^{-1}$$ at an angle 30$$\Upsilon$$ with the horizontal, it remains in the air for ......... s.

(Take, g = 10 ms$$^{-2}$$)