# physics

The gravitational field strength of an unknown planet is 15.5 N/kg on its surface. Calculate the value of g if the planets mass and radius were both doubled.

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1. F = m g = G M m /r^2
so
g = G M/R^2

double m, double g
double R , divide by 4

so
15.5 / 2

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posted by Damon

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