An aeroplane is moving with a velocity $u$. It drops a packet from a height $h$. The time $t$ taken by the packet in reaching the ground will be

An aeroplane moving horizontally with a speed of $180\, km/hr$ drops a food packet while flying at a height of $490\, m$. The horizontal range is........$m$.

$A$ 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 $\,m$)

$A$ ball of mass $0.2 \ kg$ is thrown from a height of $1 \ m$ with an initial velocity of $\sqrt{10} \ m/s$ at an angle of $45^{\circ}$ with the horizontal. Assuming acceleration due to gravity $g = 10 \ m/s^2$,the modulus of the momentum increment during the total time of motion in $kg \cdot m/s$ is:

An aeroplane is flying in a horizontal direction with a velocity of $540 \ km/h$ at a height of $1960 \ m$. When it is vertically above the point $A$ on the ground,a body is dropped from it. The body strikes the ground at point $B$. The distance $AB$ is equal to $(g = 9.8 \ m/s^2)$ (in $m$)

$A$ ball is thrown from a rooftop at an angle of $45^\circ$ above the horizontal. It hits the ground a few seconds later. At what point during its motion does the ball have $(a)$ greatest speed, $(b)$ smallest speed, and $(c)$ greatest acceleration? Explain.