The angular momentum of a rotating body is doubled, its K.E. of rotation becomes

Options

A. Two times
B. Four times
C. Halved
D. Eight times

Answer

b

Explanation

`L = I omega" "K.E. = (1)/(2) I omega^(2) = E`
`(L_(1))/(L) = sqrt((E_(1))/(E))" "I omega^(2) = 2E" "(Iomega)^(2) = 2EI`
`2 = sqrt((E_(1))/(E))" "therefore" "E_(1) = 4E`