A solid sphere of mass $1\ kg$ rolls on a table with linear speed $1\ m/s$. Its total kinetic energy is .......... $J$

A solid circular disc of mass $50 \mathrm{~kg}$ rolls along a horizontal floor so that its center of mass has a speed of $0.4 \mathrm{~m} / \mathrm{s}$. The absolute value of work done on the disc to stop it is____ $\mathrm{J}$.

A hoop of radius $2 \;m$ weighs $100\; kg$. It rolls along a horizontal floor so that its centre of mass has a speed of $20\; cm/s$. How much work has to be done to stop it?

A flywheel of moment of inertia $0.32\ kg-m^2$ is rotated steadily at $120\,rad/\sec $ by a $50\,W$ electric motor. The kinetic energy of the flywheel is.......... $J$

A solid sphere of mass $m$ and radius $R$ is rotating about its diameter. A solid cylinder of the same mass and same radius is also rotating about its geometrical axis with an angular speed twice that of the sphere. The ratio of their kinetic energies of rotation $E_{sphere}/E_{cylinder}$ will be

Three particles are situated on a light and rigid rod along $Y$axis as shown in the figure. If the system is rotating with an angular velocity of $2\,rad/\sec $about $X$axis, then the total kinetic energy of the system is ...... $J$