Net force on three collinear charges using Coulomb's law

[PatrickGeddes]

I did this problem just the way I took notes on it in class and keep coming up with the wrong answer. Please help I've spent nearly 2 hours on this one simple problem. Thanks.
Problem: Three point charges lie along a straight line as shown in the figure below, where q1 = 6.36 µC, q2 = 1.56 µC, and q3 = -1.84 µC. The separation distances are d1 = 3.00 cm and d2 = 2.00 cm. Calculate the magnitude and direction of the net electric force on each of the charges.

 

[tms]

You have to show your work so far.

 

[PatrickGeddes]

Ok sorry, first time using the site. I did F of q1 on q2 is ((8.99x10^9) x .00000636 C x .00000156 C)/.0009 m=99.10576 N and F of q3 on q2 is ((8.99x10^9) x -.00000184 C x .00000156 C)/.0016 m=-286.72 N. Then for the Force on the middle charge I just added them together to get -187.8 N.

 

[PatrickGeddes]

Is this enough work so far?