From the top of a tower of height $40\,m$,a ball is projected upwards with a speed of $20\,m/s$ at an angle of elevation of $30^{\circ}$. The ratio of the total time taken by the ball to hit the ground to its time of flight (time taken to come back to the same elevation) is (take $g=10\,m/s^2$).

$A$ gun can fire shells with maximum speed $v_0$ and the maximum horizontal range that can be achieved is $R = \frac{v_0^2}{g}$. If a target farther away by distance $\Delta x$ (beyond $R$) has to be hit with the same gun,show that it could be achieved by raising the gun to a height at least $h = \Delta x \left[ 1 + \frac{\Delta x}{R} \right]$.

$A$ hiker stands on the edge of a cliff $490 \ m$ above the ground and throws a stone horizontally with an initial speed of $15 \ m \ s^{-1}$. The speed with which it hits the ground is (in $m \ s^{-1}$)

$A$ plane is flying horizontally at $98 \, m/s$ and releases an object which reaches the ground in $10 \, s$. The angle made by the object with the horizontal while hitting the ground is ......... $^o$.

$A$ ball is thrown upward from the top of a building at an angle of $30^{\circ}$ to the horizontal and with an initial speed of $20 \,m/s$. If the ball strikes the ground after $3 \,s$, then the height of the building is (acceleration due to gravity $g = 10 \,m/s^2$) (in $\,m$)

An aeroplane moving horizontally with a speed of $720 \, km/h$ drops a food packet while flying at a height of $396.9 \, m$. The time taken by the food packet to reach the ground and its horizontal range are (Take $g = 9.8 \, m/s^2$):