A bullet of mass $0.1\,kg$ is fired with a speed of $100\, m/sec$, the mass of gun is $50\, kg$. The velocity of recoil is ........ $m/sec$

A cart loaded with sand moving with velocity $v$. Sand is falling through the hole as shown in diagram then after falling on the ground sand is

A ball will a speed of $9\, m / s$ collides with another identical ball at rest. After the collision, the direction of each ball makes an angle of $30^{\circ}$ with the original direction. The ratio of velocities of the balls after collision is $x : y$ where $x$ is........

A rifle man, who together with his rifle has a mass of $100\,kg$, stands on a smooth surface and fires $10$ shots horizontally. Each bullet has a mass $10\,g$ and a muzzle velocity of $800\,ms ^{-1}$. The velocity which the rifle man attains after firing $10$ shots is $..........\,ms^{-1}$

An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass $1\, kg$ moves with a speed of $12 \,m s^{-1}$ and the second part of mass $2\, kg$ moves with $8 \,m s^{-1}$ speed. If the third part files off with $4 \,m s^{-1}$ speed, then its mass is ......... $kg$

A $1 \;kg$ stationary bomb is exploded in three parts having mass $1: 1: 3$ respectively. Parts having same mass move in perpendicular direction with velocity $30\; ms ^{-1}$, then the velocity of bigger part will be