Physics  Charges at an angle (check + help)
posted by Anonymous .
Three charged objects are located t the vertices of a right triangle. Charge A (5*10^6) has Cartesian coordinates (0,4; Charge B (5.0*10^6) is at the origin; charge c (+4.0*10^6) has coordinates (5,0), where the coordinates are in meters. What is the net force on each charge.
Ans: I found the charge on B by finding the force F(a to b) and similarly the hypotenuse force and using the cosine rule and sine rule i found the direction and the net charge but when i try the same on point charges A and C i do not get the answer. Where am i going wrong?

Pick a charge: Say B. Find Fab and Fac. Note: Fba=Fab and Fca=Fac
so you have now only one other force, Fbc. Fcb=Fbc
So you have had to calculate only three pairs of charges.
The for magnitude, consider NOT using the trig resolutions, do this
Fa^2= Fab^2+Fac^2
Fb^2=Fba^2+Fbc^2
Fc^2=Fca^2+Fcb^2
That is it.