An artificial satellite of mass m revolves around the earth at a height h with a speed v. How much power (energy per second) will it tequire to keep itself moving with constant speed in the orbit of radius r ?

Options

A. `(mv ^(3))/(r )`
B. `1/2 mv ^(2)`
C. `(6mM_(e))/((R_(e) + h))`
D. 0

Answer

D

Explanation

Speed of satellite is constant, so by work energy theorrm,
`W = K _(f) - K _(i)`
`W=1/2 mv ^(2) -1/2 mv ^(2)`
`W =0`
As, work on satellite is zero, so power required will, also be zero, i.e. `P = (W)/(t) =0`