A body of mass 𝑚 𝑘𝑔 is rotating in a vertical circle at the end of a string of length 𝑟 metre. The difference in the kinetic energy at the top and bottom of the circle is

Question: A body of mass 𝑚 𝑘𝑔 is rotating in a vertical circle at the end of a string of length 𝑟 metre. The difference in the kinetic energy at the top and bottom of the circle is