A packet, dropped from a stationary helicopter, hovering at a height  $\text{'}h\text{'}$ from the ground level, reaches the ground in $12 \text{s}$.  Calculate

(i) The value of $h$   

(ii) The final velocity of the packet on reaching the ground. 

($\mathrm{Take} g=9.8 \mathrm{m} {\mathrm{s}}^{-2}$)

A boy drops a stone from a cliff, which reaches the ground in $8 \text{s}$. Calculate

(i) the final velocity of the stone,

(ii) the height of the cliff. 

($\mathrm{Take} \mathrm{g}=9.8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$)

To estimate the height of a bridge over a river, a stone is dropped from the bridge. It takes $3$ seconds to touch the surface of water. Calculate the height of the bridge and the velocity with which it hits the surface of water. [Take $g=9.8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$].

A stone dropped from a cliff on the surface of the Moon, reaches the surface of the moon in $30 \text{s}$. If the acceleration due to gravity of the moon is $1.63 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$ . Calculate

(i) the height of the cliff,

(ii) the velocity of the stone on touching the surface of the Moon.

A stone thrown vertically upward takes $3 \text{s}$ to attain the maximum height. Calculate,

(i) the initial velocity of the stone.

(ii) the maximum height attained by the stone.

(Take $g=9.8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$)

A stone thrown vertically upward returns to the thrower in $4 \mathrm{s}$ Calculate

(i) the initial velocity of the stone 

(ii) the maximum height attained by the stone. Take  $g=10 \mathrm{m} {\mathrm{s}}^{-2}$.