Combined gravitational field strength

[superaznnerd]

Homework Statement

2 masses, 5k and 10kg are fixed in place at the coordinates 1,0 and 1,1 respectively. what combined gravitational field strength do they produce at the point 0,0?

Homework Equations

g = GM/r^2

The Attempt at a Solution

total g = G(5)/(1)^2 +G(5)/2
not the right answer though -- answer is 6.16 X 10^-10 @ 22.5 degrees
please help!

 

[ideasrule]

You can't add them like that because the 2 fields point in different directions. You have to add them vectorially, using the Pythagorean theorem.