A research satellite of mass `200 kg` circles the earth in an orbit of average radius `3 R//2`, where `R` is the radius of the earth. Assuming the gravitational pull on the mass of `1 kg` on the earth's surface to be `10 N`, the pull on the satellite will be

Options

A. `890N`
B. `889N`
C. `885N`
D. `892N`

Answer

B

Explanation

Force between earth and mass of 1kg is
`F=(GM_(E)xx1)/(R_(E)^(2))=(GM_(E))/(R_(E)^(2))......(i)`
Where `M_(g)` is the mass of the earth and `R_(E)` is the radius of the earth respectively.
`F'=(GM_(E)xx200)/((3/2 R_(E))^(2))......(ii)`
Dividing (ii) by (i), we get `(F')/F=800/9`
`F'=(800F)/9=800/9xx10N ( :' F=10N` (given))
`=8000/9N =889N`