$A$ cricket ball is thrown up with a speed of $19.6 \ m/s$. The maximum height it can reach is ......... $m$.

$A$ stone falls freely under gravity. It covers distances $h_1, h_2$ and $h_3$ in the first $5 \ s$,the next $5 \ s$ and the next $5 \ s$ respectively. The relation between $h_1, h_2$ and $h_3$ is:

If the water falls from a dam into a turbine wheel $19.6 \ m$ below,then the velocity of water at the turbines is .................. $m/s$ (take $g = 9.8 \ m/s^2$).

$A$ ball is thrown vertically upwards with a velocity of $20 \; m s^{-1}$ from the top of a multistorey building. The height of the point from where the ball is thrown is $25.0 \; m$ from the ground. How long will it be in $seconds$ before the ball hits the ground? Take $g = 10 \; m s^{-2}$.

Two bodies of masses $m_1$ and $m_2$ are dropped from two different heights $h_1$ and $h_2$ respectively. The ratio of the times taken by the two masses to touch the ground is (neglect air resistance)

Can a particle moving in a straight line have zero velocity and non-zero acceleration at any instant? Give an example.