A particle is projected with speed $u$ at angle $\theta$ with horizontal from ground. If it is at same height from ground at time $t_1$ and $t_2$, then its average velocity in time interval $t_1$ to $t_2$ is .........

A body is projected from the ground at an angle of $45^{\circ}$ with the horizontal. Its velocity after $2s$ is $20 \,ms ^{-1}$. The maximum height reached by the body during its motion is $m$. (use $g =10\, ms ^{-2}$ )

A stone is projected at angle $30^{\circ}$ to the horizontal. The ratio of kinetic energy of the stone at point of projection to its kinetic energy at the highest point of flight will be :

A body of mass $0.5 \,kg$ is projected under gravity with a speed of $98 \,m/s$ at an angle of ${30^o}$ with the horizontal. The change in momentum (in magnitude) of the body is ......... $N-s$

A projectile is thrown with a velocity of $50\,\, ms^{^{-1}}$ at an angle of $53^o$ with the horizontal .Choose the incorrect statement

A projectile crosses two walls of equal height $H$ symmetrically as shown The height of each wall is  ........ $m$