Physics

Problem

A satellite circles the Earth at an altitude of

400\,\text{km}

with a speed of

7.70\,\text{km s}^{-1}

. The acceleration due to gravity at that altitude is measured to be

8.7\,\text{m s}^{-2}

. From these data, the radius of the Earth is calculated to be closest to a)

6.8\times10^{6}\,\text{m}

6.0\times10^{6}\,\text{m}

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

7.2\times10^{6}\,\text{m}