A satellite is shifted from a circular orbit of radius to a lower circular orbit of…

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

500\,\text{kg}

satellite is shifted from a circular orbit of radius

4R_{\text{E}}

to a lower circular orbit of radius

2R_{\text{E}}

around Earth. Find the work done by an external agent in this process. (Use

G M_{\text{E}}/R_{\text{E}} = 6.3 \times 10^{7}\,\text{J kg}^{-1}

.) (a)

-7.9\times10^{9}\,\text{J}

(b)

+3.9\times10^{9}\,\text{J}

(c)

-3.9\times10^{9}\,\text{J}

(d)

-1.6\times10^{10}\,\text{J}