PLSSS PHYSICS HELP??? im past desperate!! Two charges, qA and qB, are at rest near a positive test charge, qT?

Okay, haven't don't this for a bit... By the way, I hate this stuff. Here's my solution:

Using Coulomb's Law.

f_TA = 3.6u * 7.2u * K / (3.7e-2)^2 = 170.2nN

f_TB = -5.5u * 7.2u * K / (6.8e-2)^2 = -76.97nN

So we have:

f_T = 170.2n /_ 35° - 76.97n /_ 139°

That's the sum of the forces on f_T. If you're wondering what ' /_ ' is, it's my incredibly dodgy phasor symbol that I probably shouldn't be using because it implies that there's a complex part and the vector is spinning, which it isn't. I dunno what you're doing it, but we use it in Electrical Engineering for short hand.

Anyways, now we convert the phasors to rectangular form, and add them.

i and j are orthogonal unit vectors.

f_T = 170.2n ( cos(35°) i + sin(35°) j) - 76.97n ( cos(139°) i + sin(139°) j )

f_T = 197.5n i + 47.13 j

Now we have the sum of the forces on f_T broken up into a vertical and horizontal component.

For the magnitude:

|f_T| = |197.5n i + 47.13 j| = 203.1nN

For the direction:

Arg(f_T) = Arg(197.5n i + 47.13 j) = 13.42°

Well, there might be a mistake somewhere, but that's how you do it.

By the way, what year is this for?

Edit:

Oops, left out the nano from K.