A particle of mass $m$ moving with a speed $v$ hits elastically another stationary particle of mass $2\ m$ in a fixed smooth horizontal circular tube of radius $R$. Find the time when the next collision will take place?
$\frac{{\pi R}}{v}$
$\frac{{2\pi R}}{v}$
$\frac{{4\pi R}}{v}$
$\frac{{6\pi R}}{v}$
Explain oblique collision.
A sphere strikes a wall and rebounds with coefficient of restitution $1/3$. If it rebounds with a velocity of $0.1\, m/sec$ at an angle of $60^o$ to the normal to the wall, the loss of kinetic energy is
Two massless string of length $5\, m$ hang from the ceiling very near to each other as shown in the figure. Two balls $A$ and $B$ of masses $0.25 \,kg$ and $0.5 \,kg$ are attached to the string. The ball $A$ is released from rest at $a$ height $0.45\, m$ as shown in the figure. The collision between two balls is completely elastic. Immediately after the collision, the kinetic energy of ball $B$ is $1\, J$. The velocity of ball $A$ just after the collision is
A body of mass m having an initial velocity $v$, makes head on collision with a stationary body of mass $M$. After the collision, the body of mass $m$ comes to rest and only the body having mass $M$ moves. This will happen only when
A body of mass $m$ moving with velocity $v$ elastic collides head on with another body of mass $2\,\,m$ which is initially at rest. The ratio of $K.E.$ of the colliding body before and after collision will be