Planet Y has a radius that is one-third of Earth’s radius

PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Planet Y has a radius that is one-third of Earth’s radius. The acceleration due to gravity at the surface of planet Y is measured to be

15\,\text{m/s}^2

. Take Earth’s mass

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

and radius

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

. (a) Determine the mass

M_Y

of planet Y. (b) Find the ratio

\dfrac{M_Y}{M_E}