$A$ player throws a ball that reaches another player in $4\,s$. If the height of each player is $1.5\,m$,the maximum height attained by the ball from the ground level is .......... $m$.

There are three steps,each with a height of $10 \, cm$ and a width of $20 \, cm$. What minimum horizontal velocity (in $m/s$) must be given to a ball from the top step so that it clears all three steps?

An aeroplane is moving with horizontal velocity $u$ at height $h$. The velocity of a packet dropped from it on the earth's surface will be ($g$ is acceleration due to gravity).

$A$ ball of mass $m=1 \, kg$ is thrown from the top of a building with initial velocity $v=(20 \, m/s) \hat{i} + (24 \, m/s) \hat{j}$ at time $t=0$. The change in the potential energy of the ball between $t=0$ and $t=6 \, s$, if the ball does not hit the ground, is (assume $g=10 \, m/s^2$): (in $ \, J$)

$A$ cannon ball is fired from the top of a $55 \ m$ high cliff with an initial speed of $50 \ m \ s^{-1}$. The speed of the cannon ball while hitting the ground in $m \ s^{-1}$ is (acceleration due to gravity $= 10 \ m \ s^{-2}$):

In the figure shown,find the velocity of the particle at point $P$ $(g = 10\,m/s^2)$.