A projectile is thrown with a velocity of $10\,m / s$ at an angle of $60^{\circ}$ with horizontal. The interval between the moments when speed is $\sqrt{5 g}\,m / s$ is $..........\,s$ $\left(g=10\,m / s ^2\right)$.

A particle is projected with a velocity of $30\,m / s$, at an angle of $\theta_0=\tan ^{-1}\left(\frac{3}{4}\right)$ After $1\,s$, the particle is moving at an angle $\theta$ to the horizontal, where $\tan \theta$ will be equal to $\left(g=10\,m / s ^2\right)$

Two bodies are projected from ground with same speeds $40 ms ^{-1}$ at two different angles with respect to horizontal. The bodies were found to have same range. If one of the body was projected at an angle of $60^{\circ}$, with horizontal then sum of the maximum heights, attained by the two projectiles, is $.......m$. (Given $g =10 ms ^{-2}$ )

For a given angle of the projectile if the initial velocity is doubled the range of the projectile becomes

Two balls are projected from the same point simultaneously.First ball is projected vertically upwards and the second ball at an angle of projection $60^o$ to the ground level. Both the balls reach the ground simultaneously. The ratio of their velocities are

A cricketer can throw a ball to maximum horizontal distance of $100\,m$ . With the same speed how much high above the ground can the cricketer throw the same ball   ......... $m$