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
(A) \dfrac{mg}{r}
(B) \dfrac{2mg}{r}
(C) 2𝑚𝑔r
(D) 𝑚𝑔r
Answer: option (C)
Solution:
