A satellite is in a circular orbit round the earth at an altitude R above the earth's surface, where R is the radius of the earth. If g is the acceleration due to gravity on the surface of the earth, the speed of the satellite is

Options

A. `sqrt(2Rg)`
B. `sqrt(Rg)`
C. `sqrt((Rg)/2)`
D. `(sqrt(Rg))/(4)`

Answer

C

Explanation

Orbital velocity `(v_0)` at a height h above the earth’s surface is given by
`v_0 = R_e sqrt((g)/(R_e + h))`
Given,`h = R_e`
`therefore v_0 = R sqrt((g)/(2R))`
`= sqrt((2g)/(2))`