Answer to Question #108118 in Classical Mechanics for VIVEK SINGH

Question

(a) What is the approximate force of gravity on a 70-kg person due to the Andromeda galaxy, assuming its total mass is 1013 that of our Sun and acts like a single mass 2 Mly away?

Answer 1

1 Mly =$9.45\times10^{21}m$

2 Mly =$18.9\times10^{21}m$

mass of sun =$1.989 × 10^{30} kg$

mass of  Andromeda=$1013\times1.989\times10^{30}=2\times10^{31}kg$

Force of gravity is given by $G\frac{Mm}{r^2}$

Force = $6.67259 \times 10^{-11}\times\frac{2\times10^{31}\times70}{(1.89\times10^{30})^2}=2.61\times10^{-40}N$