Newtons Laws EX 38

The strength of the gravitational field is also called the gravitational acceleration. The gravitational acceleration of a particle which is placed at some distance $r$ from an object of mass $m$ is equal to:

$g=\frac{Gm}{r^2}$

where $G=6.67\times 10^{-11}$.

(a) Neptune: $g=\frac{(6.67\times 10^{-11})(1.03\times 10^{26})}{(2.43\times 10^7{)}^2}=11.6m/s^2$

(b) Jupiter: $g=\frac{(6.67\times 10^{-11})(1.9\times 10^{27})}{(7.14\times 10^7{)}^2}=24.8m/s^2$

(c) Neutron star: $g=\frac{(6.67\times 10^{-11})(10^{30})}{(2\times 10^4{)}^2}=1.67\times 10^{11}m/s^2$