$A$ stone is projected at an angle of $60^o$ from the ground level and strikes at an angle of $30^o$ on the roof of a building of height $h = 30 \, m$. Find the speed of projection (in $m/s$) of the stone.

$A$ bomber plane moves horizontally with a speed of $500 \ m/s$ and a bomb released from it strikes the ground in $10 \ s$. The angle with the horizontal at which it strikes the ground will be $(g = 10 \ m/s^2)$.

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 $m$)

$A$ bomber plane moves horizontally with a speed of $500\, m/s$ and a bomb released from it strikes the ground in $10\, s$. The angle at which it strikes the ground is $(g = 10\, m/s^2)$.

$A$ 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: