The distance between two objects is increased by 3 times the original distance. How will this change the force of attraction between the two objects?

Question

mrnood · Answer

I assume it means gravitational attraction

The force , it the objects are at a distance r is
F = GMm/r^2

If the distance increases to 3r then the force is#

F= GMm/(3r)^2

So you can work out the ration of the forces from that (independent of any thing but the distance - i.e. you do not need to know G,  M or m

mrnood · Answer

^^ Mistake above...

I think it means increase BY 3 times - which means that it is now 4r away...

Use that in the equations above - the maths is still the same