Physics

Problem

A spacecraft of mass

2000\,\text{kg}

moves from a circular orbit of radius

5R_E

to another of radius

2R_E

about Earth (

R_E = 6.4\times10^{6}\,\text{m}

). Using

G = 6.67\times10^{-11}\,\text{N\,m}^{2}\text{kg}^{-2}

and

M_E = 6.0\times10^{24}\,\text{kg}

, calculate the change in its gravitational potential energy

\Delta U = U_{\text{final}} - U_{\text{initial}}

. a)

+3.8\times10^{10}\,\text{J}

-3.8\times10^{10}\,\text{J}

-1.9\times10^{10}\,\text{J}

-7.5\times10^{10}\,\text{J}