A body of mass $m$ is moving in a horizontal circle of radius $R$ under a centripetal force equal to -$k/R^2$, where $k$ is a constant. The kinetic energy of the particle is

A pellet of mass $1 \mathrm{g}$ is moving with an angular velocity of $1 \mathrm{rad}/\mathrm{s}$ along a circle of $1$ metre. The centrifugal force is

A small coin is placed on a whirling table. The coin just begins to slip when it is placed $4 \mathrm{cm}$ from the centre of the table. If the table rotates with double the angular speed, at what distance from the centre of the table should the coin be placed so that it just starts slipping?