Consider a rubber ball freely falling from a height $h = 4.9\, m$ on a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Which one of the following graph represents the velocity as a function of time and the height as a function of time ?

Two masses of $0.25\, kg$ each moves towards each other with speed $3\, ms^{-1}$ and $1\, ms^{-1}$. Then they collide and stick together. Find the final velocity .............. $\mathrm{m} \mathrm{s}^{-1}$

If a rubber ball falls from a height $h$ and rebounds upto the height of $h / 2$. The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are :

A sphere collides with another sphere of identical mass. After collision, the two spheres move. The collision is inelastic. Then the angle between the directions of the two spheres is

A ball of mass $'m'$ moving with a speed $'u'$ under goes a head-on elastic collision with a ball of mass $(nm)$  initially at rest. The fraction of the incident energy transferred to the heaveir ball is

A ball hits the floor and rebounds after inelastic collision. In this case