(a) Derive an expression for the mean density of a spherical planet in terms of its…

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

Problem

(a) Derive an expression for the mean density of a spherical planet in terms of its surface acceleration due to gravity

g

, its radius

R

and the universal gravitational constant

G

. (b) Using

g = 9.8\,\text{m\,s}^{-2}

R = 6.37\times10^{6}\,\text{m}

and

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

, calculate the mean density of Earth.