In the figure,determine the type of collision. The masses of the blocks,and the velocities before and after the collision are given. The collision is

$A$ neutron moving with velocity $u$ collides elastically with an atom of mass number $A$. If the collision is head-on and the initial kinetic energy of the neutron is $E$, then the final kinetic energy of the neutron after the collision is:

$A$ ball falls from a height of $5\,m$ and strikes the roof of a lift. If at the time of collision,the lift is moving in the upward direction with a velocity of $1\,m/s$,then the velocity with which the ball rebounds after collision will be (assume $e = 1$):

In the elastic collision of objects,

Consider the situation as shown in the figure. The ball strikes the wall normally and the collision is elastic. The wall is moving with a velocity of $20 \ m/s$ to the right,and the ball is moving with a velocity of $10 \ m/s$ to the left. The mass of the ball is $500 \ g$. The change in the kinetic energy of the ball is $....J$.

Six identical balls are lined up in a straight groove on a horizontal frictionless surface. Two similar balls,each moving with a velocity $v$,collide elastically with the row of $6$ balls from the left. What will happen?