A spring is compressed between two toy carts of mass $m_1$ and $m_2$. When the toy carts are released, the springs exert equal and opposite average forces for the same time on each toy cart. If $v_1$ and $v_2$ are the velocities of the toy carts and there is no friction between the toy carts and the ground, then :

The momentum of a system is conserved

A lead ball strikes a wall and falls down, a tennis ball having the same mass and velocity strikes the wall and bounces back. Check the correct statement

A hemisphere of radius $R$ and of mass $4m$ is free to slide with its base on a smooth horizontal table. A particle of mass $m$ is placed on the top of the hemisphere. The angular velocity of the particle relative to hemisphere at an angular displacement $\theta $ when velocity of hemisphere $v$ is

A ball is projected at $60^o$ from horizontal at $200\, m/s$. At maximum height during its  flight it explodes into $3$ equal fragments. Out of them one part travel at $100\, m/s$  vertically up while other at $100\, m/s$ vertically down, then third part will have  speed just after explosion :-

A mass of $1 \;kg$ is thrown up with a velocity of $100 \;m / s$. After $5 \;seconds$, it explodes into two parts. One part of mass $400\; g$ comes down with a velocity $25 \;m / s$ Calculate the velocity of other part