Question

A hollow sphere rolls on a horozontal surface without slipping. Then percentages of rotational kinetic energy in total energy is
A. `60%`
B. `40%`
C. `72%`
D. `28%`

Answer 1

Correct Answer - B
`(KE_("rot"))/(KE_("roll"))=(K^(2)//R^(2))/(1+K^(2)//R^(2))`
`=((2)/(3))/(1+(2)/(3))=((2)/(3))/((7)/(3))=(2)/(7)=0.28=28%`.