Question 110677
According to Newton's Law of Graviation, the force of attractions between two objects varies jointly as thir masses and inversely as the square of the distance between them. 
-----------------
Basic Formula:
F = km1m2/d^2
---------------
How does the force change if each of their masses is tripled but the distance bewteen them is cut to one-third?
---------------
After modify masses and force:
F = k (3m1)(3m2)/[(1/3)d]^2
F = k 9m1m2/[d^2/9]
F = (81)[km1m2/d^2]
----------
Answer: The force is multiplied by 81.
============
Cheers,
Stan H.