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 projectile thrown with velocity $v$ making angle $\theta$ with vertical gains maximum height $H$ in the time for which the projectile remains in air, the time period is

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

A ball is thrown at different angles with the same speed $u$ and from the same point. It has the same range in both cases. If $y_1$ and $y_2$ be the heights attained in the two cases, then $y_1+y_2$ equals to

A ball is projected with kinetic energy $E$, at an angle of $60^{\circ}$ to the horizontal. The kinetic energy of this ball at the highest point of its flight will become.

Range of a bob of mass $1\, kg$ is $80\,m$ while it attains maximum height $20\,m$. Its  change in momentum in complete motion ............ $N-s$