$A$ sphere of mass $M$ and radius $R$ is attached by a light rod of length $l$ to $a$ point $P$. The sphere rolls without slipping on a circular track as shown. It is released from the horizontal position. the angular momentum of the system about $P$ when the rod becomes vertical is :
$M\sqrt {\frac{{10}}{7}\,g{\text{l}}} \,\,[{\text{l}} + R]$
$M\sqrt {\frac{{10}}{7}\,g{\text{l}}} \,\,\left[ {{\text{l}} - \,\frac{2}{5}R} \right]$
$M\sqrt {\frac{{10}}{7}\,g{\text{l}}} \,\,\left[ {{\text{l}} + \,\frac{7}{5}R} \right]$
$M\sqrt {\frac{{10}}{7}\,g{\text{l}}} \,\,\left[ {{\text{l}} + \,\frac{2}{5}R} \right]$
One end of rod of length $L$ is on horizontal plane. It is inclined at angle $\alpha$ to horizontal plane. When released its angular velocity after coming to horizontal plane is
A ring of radius $0.5\, m$ and mass $10 \,kg$ is rotating about its diameter with an angular velocity of $20 \,rad/s.$ Its kinetic energy is .......... $J$
A stick of length $L$ and mass $M$ lies on a frictionless horizontal surface on which it is free to move in any ways. A ball of mass $m$ moving with speed $v$ collides elastically with the stick as shown in the figure. If after the collision the ball comes to rest, then what should be the mass of the ball ?
A hollow sphere is rolling on a plane surface about its axis of symmetry. The ratio of rotational kinetic energy to its total kinetic energy is $\frac{x}{5}$. The value of $x$ is________.
A solid cylinder of mass $20 \;kg$ rotates about its axis with angular speed $100\; rad s ^{-1}$ The radius of the cylinder is $0.25 \;m$. What is the kinetic energy associated with the rotation of the cylinder? What is the magnitude of angular momentum of the cylinder about its axis?