Two paper screens $$A$$ and $$B$$ are separated by $$150 \mathrm{~m}$$. A bullet pierces $$A$$ and than $$B$$. The hole in $$B$$ is $$15 \mathrm{~cm}$$ below the hole in $$A$$. If the bullet is travelling horizontally at the time of hitting $$A$$, then the velocity of the bullet at $$A$$ is $$\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)$$

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$$^{-2}$$)