A projectile crosses two walls of equal height $H$ symmetrically as shown  The time of flight $T$ is given by  ........ $\sec$

Two balls are projected from the same point simultaneously.First ball is projected vertically upwards and the second ball at an angle of projection $60^o$ to the ground level. Both the balls reach the ground simultaneously. The ratio of their velocities are

A projectile fired with initial velocity $u$ at some angle $\theta $ has a range $R$. If the initial velocity be doubled at the same angle of projection, then the range will be

The range of a particle when launched at an angle of ${15^o}$ with the horizontal is $1.5 \,km$. What is the range of the projectile when launched at an angle of ${45^o}$ to the horizontal ........ $km$

A projectile fired at $30^{\circ}$ to the ground is observed to be at same height at time $3 s$ and $5 s$ after projection, during its flight. The speed of projection of the projectile is $.........\,ms ^{-1}$(Given $g=10\,m s ^{-2}$ )

The horizontal range is four times the maximum height attained by a projectile. The angle of projection is  .......... $^o$