A satellite is orbiting around the earth in an orbitin equatorial plane of radius `2R_(e)` where `R_(e)` is the radius of earth. Find the area on earth, this satellite covers for communication purpose in its complete revolution.

Options

A. `sqrt(3) piR_(e)^(2)`
B. `2R_(e)^(2)`
C. `2sqrt(3)piR_(e)^(2)`
D. `sqrt(2)piR_(e)^(2)`

Answer

C

Explanation

Gravitational potential ,
`V=(-GM)/r(rgtR)`
`V=(-GM(3R^(2)-r^(2)))/(2R^(3))(rltR)`
Potential energy,
`U=(-GMm)/r(rgtR)`
`U=(-GMm(3R^(2)-r^(2)))/(2R^(3))(rltR)`
`KE="Loss of "PE=O-U`
`KE=U`
`:. KE` will very with `r` exactly as that of `V` with sign changed.