A research satellite revolves around Earth at an altitude of above the surface

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A research satellite revolves around Earth at an altitude of

400\,\text{km}

above the surface. Calculate its orbital speed. (Take

M_{\oplus}=6.0\times10^{24}\,\text{kg}

R_{\oplus}=6.4\times10^{6}\,\text{m}

and

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