posted by lissa on .
Four identical masses of 2.7 kg each are located at the corners of a square with 1.4 m sides. What is the net force on any one of the masses?
I don't understand why im not getting it right... i need help please!!
Fopposite corner = G m^2/(1.4*sqrt2)^2
lined up with diagonal
get component along diagonal for the two adjacent sides, thus cos 45 = 1/sqrt2
Fadjacent corners = 2 G m^2 cos 45/1.4^2
= 2 G m^2 (1/sqrt 2) /1.4^2
sqrt 2 is about 1.4 so
F = G m^2 /4 + 2sqrt 2 G m^2/4
= G m^2 (1+2.8)/4
pretty close to G m^2 but do the arithmetic more accurately than I did in my head