An object of mass $5 \, kg$ is thrown vertically upwards from the ground. The air resistance produces a constant retarding force of $10 \, N$ throughout the motion. The ratio of time of ascent to the time of descent will be equal to [Use $g = 10 \, ms^{-2}$]

The initial and final velocities of a body projected vertically from the ground are $20 \,ms^{-1}$ and $18 \,ms^{-1}$ respectively. The maximum height reached by the body is (Acceleration due to gravity $= 10 \,ms^{-2}$) (in $\,m$)

When a ball is thrown up vertically with velocity $V_o$,it reaches a maximum height of $h$. If one wishes to triple the maximum height,then the ball should be thrown with what velocity?

$A$ ball is thrown upward with speed $10 \, m/s$ from the top of a tower and reaches the ground with a speed $20 \, m/s$. The height of the tower is ......... $m$. (Take $g = 10 \, m/s^2$)

$A$ ball is thrown upward with an initial velocity $V_0$ from the surface of the earth. The motion of the ball is affected by a drag force equal to $m\gamma v^2$ (where $m$ is the mass of the ball,$v$ is its instantaneous velocity,and $\gamma$ is a constant). The time taken by the ball to rise to its zenith is:

$A$ paratrooper jumps from an aeroplane and opens a parachute after $2 \ s$ of free fall and starts decelerating with $3 \ m/s^2$. At $10 \ m$ height from the ground, while descending with the help of the parachute, the speed of the paratrooper is $5 \ m/s$. The initial height of the aeroplane is . . . . . . $m$. $(g = 10 \ m/s^2)$