A particle is projected from a point $A$ with velocity $u\sqrt 2$ at an angle of $45^o$ with horizontal as shown in fig. It strikes the plane $BC$ at right angles. The velocity of the particle at the time of collision is

A football player throws a ball with a velocity of $50$ metre/sec at an angle $30 $ degrees from the horizontal. The ball remains in the air for  …… $\sec$ $(g = 10\,m/{s^2})$

A ball is projected with kinetic energy $E$ at an angle of ${45^o}$ to the horizontal. At the highest point during its flight, its kinetic energy will be

The horizontal range is four times the maximum height attained by a projectile. The angle of projection is ……… $^o$

Two particles $A$ and $B$ are moving in horizontal plane as shown in figure at $t = 0$ , then time after which $A$ will catch $B$ will be…….$s$