$A$ player throws a ball upwards with an initial speed of $29.4 \; m s^{-1}$. What is the direction of acceleration during the upward motion of the ball?

An object is thrown vertically upward with a speed of $30 \,m/s$. The velocity of the object half-a-second before it reaches the maximum height is (in $\,m/s$)

$A$ boy standing at the top of a tower of $20 \, m$ height drops a stone. Assuming $g = 10 \, m/s^2$,the velocity with which it hits the ground is ......... $m/s$.

Two balls are dropped from heights $h$ and $2h$ respectively from the Earth's surface. The ratio of the time taken by these balls to reach the Earth is

$A$ body is dropped from a certain height $h$ ($h$ is very large) and a second body is thrown downward with a velocity of $5 \, m/s$ simultaneously. What will be the difference in the heights of the two bodies after $3 \, s$?

An iron block is dropped into a deep well. The sound of the splash is heard after $4.23 \, s$. If the depth of the well is $78.4 \, m$,find the speed of sound in air in $m/s$ $\left(g = 9.8 \, m/s^2\right)$.