$A$ ball is projected at an angle of $45^{\circ}$ with the horizontal. It passes through a wall of height $h$ at a horizontal distance $d_1$ from the point of projection and strikes the ground at a distance $d_1+d_2$ from the point of projection. Then $h$ is:

$A$ particle is moving in the $xy$-plane in a circular path with its center at the origin. If at an instant the position of the particle is given by $\frac{1}{\sqrt{2}}(\hat{i}+\hat{j})$,then the velocity of the particle is along .......

$A$ sportsman runs around a circular track of radius $r$ such that he traverses the path $ABAB$. The distance travelled and displacement,respectively,are

Bullets are fired in all directions with the same velocity $u$. What is the maximum area covered by them?

Two boys conducted experiments on projectile motion with a stopwatch and noted some readings. As one boy throws a stone into the air at an angle with the horizontal,the other boy observes that after $4 \ s$,the stone is moving at an angle of $30^{\circ}$ to the horizontal,and after another $2 \ s$,it is traveling horizontally. The magnitude of the initial velocity of the stone is (Acceleration due to gravity,$g = 10 \ ms^{-2}$):

$A$ body of mass $0.6 \, kg$ is moving along a circular path of radius $1 \, m$. If the body moves with $\frac{900}{\pi}$ revolutions per minute, its kinetic energy is: (in $ \, J$)