The radius of the orbit of a satellite is r and its kinetic energy is k if the radius of the orbit is doubled then the new kinetic energy k is

Options

A. 2k
B. `(k)/(2)`
C. 4 k
D. data insufficient

Answer

B

Explanation

KE of a satellite `=(GmM_(E))/(2(R_(E)+h)`
Given KE=K
Radius of orbit `=(R_(E)+h)=r rarr K =(GmM_(E))/(2r)`
since `K prop (1)/(r ) rarr (K_(1))/(K_(2))=(r_(2))/(r_(1)) rarr (K)/(k') =(2r)/(r )`
`therefore k' =(K)/(2)`