For a projectile the ratio of maximum height reached to the square of flight time is

A boy throws a ball in air at $60^o$ to the horizontal, along a road with a speed of $10\,ms^{-1}$ $(36\, km/h)$. Another boy sitting in a passing by car observes the ball. Sketch the motion of the ball as observed by the boy in the car, if car has a speed of $(18\, km/h)$. Give explanation to support your diagram.

The maximum height reached by a projectile is $64 \mathrm{~m}$. If the initial velocity is halved, the new maximum height of the projectile is_________.$\mathrm{m}$.

Two projectiles $A$ and $B$ are thrown with the same speed but angles are $40^{\circ}$ and $50^{\circ}$ with the horizontal. Then

Two balls are thrown simultaneously from ground with same velocity of $10\,m / s$ but different angles of projection with horizontal. Both balls fall at same distance $5 \sqrt{3}\,m$ from point of projection. What is the time interval between balls striking the ground?

A body is thrown at angle $30^{\circ}$ to the horizontal with the velocity of $30\; m / s$. After $1\;sec$, its velocity will be (in $m/s$) $\left(g=10\; m / s ^{2}\right)$