A particle of mass 10 g is kept of the surface of a uniform sphere of mass 100 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere. (Take `G = 6.67 xx 10^(-11) Nm^(2)//kg^(2)` ?

Options

A. `6.67 xx 10^(-9) J`
B. `6.67 xx 10^(10) J`
C. `13.34 xx 10^(-10) J`
D. `3.33xx 10^(-10) J`

Answer

B

Explanation

`implies` Work = Change in potential energy `= U_2 - U , `
`W- (GMm)/(oo) - (-(GMm)/r)`
`=0+(6.67 xx 10^(-11) xx 100 xx 10 xx 10^3 )/(10 xx 10^(-2))`
` [ :. (GMm)/(oo) = 0]`
`:. W = 6.67 xx 10 ^(-10) J`