Question

A planet exerts a gravitational force of magnitude 4e22 N on a star. If the planet were 3 times closer to the star (that is, if the distance between the star and the planet were 1/3 what is is now), what would be the magnitude of the force on the star due to the planet

Answer 1

Answer:

$3.6\times10^{23} N$

Explanation:

$F=\frac{GmM}{r^2}=4\times10^{22} N$

$F'=\frac{GmM}{(r/3)^2}=9\frac{GmM}{r^2}=9\times4\times10^{22}=3.6\times10^{23} N$