Quick question about magnetic fields

[formulajoe]

given that B = (6x, -9y, 3z) find the total force experienced by a rectangular loop in the z = 0 plane.
1<x<3
1<y<2

i used the torque equation, but my question is if i have to do the integration for all 4 sides of the rectangle.
T = int(dl cross B)

 

[dextercioby]

I don't get it,what's the curreent in the loop?

Daniel.

 

[formulajoe]

oh yea, there's 5 A in the counterclockwise direction

 

[dextercioby]

Okay,then.U know the expression for the electromagnetic force (the one containing the cross product) in diff.form.Apply it for the 4 sides of the rectangle and do those integrations (u need them,because the field is not constant) .Then simply add the 4 resulting vectors...

Daniel.