In real world, all objects obey Newton’s thirds law. A coil with current flowing within produces magnetic field that exerts force on the current of the coil itself. If the coil is not round, this force tends to make the coil round. But the total force on the coil is zero and the coil does not move as a whole. However, when this force is computed using the Lorentz force law, the total force is not zero. So, Newton is unhappy with Lorentz. In the following, we take the isosceles triangle coil ABC shown in Figure 1 and compute the total force numerically
Please read the article at
Unhappiness of Newton with Lorentz and triangular coil experiment
http://pengkuanem.blogspot.com/2013/05/unhappiness-of-newton-with-lorentz-and.html
or
http://www.academia.edu/3500211/Unhappiness_of_Newton_with_Lorentz_and_triangular_coil_experiment