Moon revolves around the earth in an orbit of radius $R$ with time period of revolution $T$. It also rotates about its own axis with a time period $T$. If mass of the moon is $M$ and its radius is $r$, the total kinetic energy of the moon is
The spinning of the Diwali cracker 'ground chakkar' involves the concept of
A clock is designed based on the oscillation of a spring-block system suspended vertically in the absence of air-resistance. Assume it shows the correct time when a spring of stiffness $k$ and block is mass $m$ are used. If the block is replaced by another block of mass $4 m$, choose the correct option
A body of mass 6 kg is moving with a uniform velocity $4 \mathrm{~ms}^{-1}$. Its velocity changes to $6 \mathrm{~ms}^{-1}$ when a force of 12 N acts on it. Then its displacement is