In the figure shown,find the velocity of the particle at point $P$ $(g = 10\,m/s^2)$.

$A$ ball is projected upwards from the top of a tower with a velocity $50 \, m/s$ making an angle $30^\circ$ with the horizontal. The height of the tower is $70 \, m$. After how many seconds from the instant of throwing will the ball reach the ground? ........ $s$

$A$ fighter plane is flying horizontally at an altitude of $1.5\, km$ with a speed of $720\, km/h$. At what angle of sight (with respect to the horizontal) should the pilot drop the bomb when the target is seen,in order to hit the target?

$A$ 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 $h = \Delta x \left[ 1 + \frac{\Delta x}{R} \right]$.

$A$ cannon placed on a cliff at a height of $375 \ m$ fires a cannonball with a velocity of $100 \ ms^{-1}$ at an angle of $30^{\circ}$ above the horizontal. The horizontal distance between the cannon and the target is (Acceleration due to gravity $= 10 \ ms^{-2}$)

$A$ ball is projected from the top of a tower with a velocity of $5 \, m/s$ at an angle of $53^o$ to the horizontal. Its speed when it is at a height of $0.45 \, m$ from the point of projection is ........ $m/s$.