A sphere of mass m rolls on a plane surface.Find its kinetic energy t an instant when its centre moves with speed v.

Answer

A, B

Explanation

A sphere having mass m roll on a plane surface. Let its radius be R. Its centre moves with a velocity . Therefore
Kinetic energy `=1/2Iomega^2+1/2mv^2`
`=1/2xx(2/5mR^2)xxv^2/R^2+1/2mv^2`
`=2/10mv^2+1/2mv^2`
`((2+5)mv^2)/10=7/10mv^2`