A thin metal hoop of radius 0.25 m and mass 2 kg starts from test and rolls down an inclined plane. If its linear velocity on reachign the foot of the plane is `2ms^(-1)`, what is its rotational K.E. at that instant?

Explanation

Here R=0.25 m
`M=2kg`
`V=2ms^(-1)`
Rotational K.E `=1/2 I omega^(2)=1/2 MR^(2)xx(V/R)^(2)`
`=1/2 MV^(2)=1/2xx2xx4=4J`