A body of mass one kg is revolving in a vertical circle of radius 10 m . The different in kinetic energies of the mass at top and at bottom of the circle is given by (Take `g =10 ms^(-2)`)

Options

A. 200 joule
B. 300 joule
C. 400 joule
D. 500 joule

Answer

A

Explanation

Velocity at top , `F = sqrt(Rg) ` , Velocity at bottom = `sqrt(5Rg)`
Difference in K.E = `1/2 m(5Rg) -1/2 m(Rg) , " Kg = 2mRg" = 2xx1 xx 10 xx 10 = 200 ` joule .