A disc of mass 4 kg and of radius 1 m rolls on a horizontal surface without slipping such that the velocity of its centre of mass is `10" cm sec"^(-1)`, Its rotatonal kinetic energy is

Options

A. 0.005 J
B. 0.02 J
C. `0.03 J`
D. 0.01 J

Answer

D

Explanation

`KE_("rotational") = (1)/(2) I omega^(2)`
`KE_("rotational " ) = (1)/(2) ( (1)/(2) (4) (1)^(2)) (0.1)^(2)`
`KE_("rotational ") = 0.01 J`