$A$ billiard ball of mass $M$,moving with velocity $v_1$ collides with another ball of the same mass but at rest. If the collision is elastic,the angle of divergence after the collision is (in $^{\circ}$)

$A$ steel ball of radius $2 \,cm$ is at rest on a frictionless surface. Another steel ball of radius $4 \,cm$ moving with velocity of $81 \,cm \,s^{-1}$ collides elastically with the ball which is at rest. After collision, the ball with radius of $2 \,cm$ moves with a speed of:

$A$ body of mass $m$ is at rest. Another body of the same mass moving with velocity $V$ makes a head-on elastic collision with the first body. After the collision,the first body starts to move with velocity:

$A$ heavy body moving with a velocity of $6\,ms^{-1}$ collides elastically with a light body (whose mass is half of the mass of the heavy body) at rest. The velocity of the light body will be (in $ms^{-1}$):

As shown in the figure,a pendulum $A$ is released from an angle of $30^{\circ}$ with the vertical and strikes a pendulum $B$ of equal mass. After the collision,to what height (in $m$) will pendulum $A$ rise? Neglect the size of the pendulum and assume the collision is perfectly elastic.

$A$ particle of mass $m$ moving with velocity $\vec{v_1}$ undergoes a two-dimensional elastic collision with another particle of mass $m$ at rest. If the particles move with velocities $\vec{v_1}'$ and $\vec{v_2}'$ after the collision,what is the angle between them in degrees?