A body having M.I of `5kg-m^(2)` about its axis of rotation is rotating with angular velocity of 6 rad/s. The kinetic energy of the rotating body is the same as that of a body of mass 5 kg moving with a speed of

Options

A. 2 m/s
B. 4 m/s
C. 6 m/s
D. 8 m/s

Answer

C

Explanation

K.E. of the rotating body `=(1)/(2)Iomega^(2)`
K.E. of the body having translational motion `=(1)/(2)mv^(2)`
`therefore" "(1)/(2)Iomega^(2)=(1)/(2)mv^(2)" "therefore (1)/(2)xx5xx36=(1)/(2)xx5xxv^(2)`
`therefore" "v^(2)=36" "therefore v=6m//s`