Square Loop and Magnetic Forces

[ecthelion4]

I need to prove that the magnetic force done to a square loop with a current by an uniform magnetic field is zero. The exact problem is this:

A square loop of sides of length l and carrying a current I lies at the xy plane in the presence of a uniform magnetic field B(vector) = B<. Show by calculating explicitly the magnetic force vector on each segment and then adding all the vectors that the magnetic force is 0

I'm pretty sure you can calculate the force on a wire segment with F=(current through wire)(length of wire)x(magnetic field). Can I apply that in this problem or would a different approach be more suitable? The problem also states that I need to calculate a torque, I honestly have no idea WHERE I can do that in this problem.

 

[Doc Al]

I'm pretty sure you can calculate the force on a wire segment with F=(current through wire)(length of wire)x(magnetic field). Can I apply that in this problem or would a different approach be more suitable?

Yes, use that to calculate the force on each segment.

The problem also states that I need to calculate a torque, I honestly have no idea WHERE I can do that in this problem.

Depending on the direction of the field, there may be a net torque on the loop.