PHYSICS/ GRAVITATIONAL CONSTANT
posted by CJ on .
Three masses are arranged in the (x,y) plane. The X and Y units are meters
4kg at (1,5
3kg at (1,1)
5kg at (0,0)
What is the magnitude of theresulting force on the 5kg mass at the origin? The universal gravitational constant is 6.673e11 N*m^2/kg^2. Answer in units of N.

It is rather simple. Figure the two forces, and add as vectors.

I DID THAT BUT THE ANSWER IS WRONG. IDON'T KNOW WHY

Let me show you a shortcut:
fx= G5(4/1^1)(1)+G5(3/1)(+1) That is the resultant fx
Fy=G5(5/5^2)(+1)+G5(3/1)(+1) that is the resultant fy
fx=G5(1)
fy=G5(1/5+3)=G5(15/5)=5G*3
magnitude= 5G*sqrt(1+9)=5Gsqrt10 
If you don't understand that shortcut,don't do it.