Ball $A$ moving at $12\  m/s$ collides elastically with $B$ as shown. If both balls have the same mass, what is the final velocity of ball $A$ ? ................$m/s$

$A$ smooth sphere is moving on a horizontal surface with a velocity vector $(\,2\,\hat i + 2\,\hat j\,)$ $m/s$ immediately before it hit a vertical wall. The wall is parallel to vector $\hat j$ and coefficient of restitution between the sphere and the wall is $e = 1/2$ . The velocity of the sphere after it hits the wall is

Two bodies $A$ and $B$ collide as shown in Fig. $(i)$ and $(ii)$ Which statement is true ?

A body falling from a height of $10\,m$ rebounds from hard floor. If it loses $20\%$ energy in the impact, then coefficient of restitution is

A $1.0\, kg$ ball drops vertically into a floor from a height of $25\, cm$. If rebounds to a height of $4\ cm$. The coefficient of restitution for the collision is

A truck moving on horizontal road towards east with velocity $20\, ms^{-1}$ collides elastically with a light ball moving with velocity $25\, ms^{-1}$ along west. The velocity of the ball just after collision