Final answer:
The change in measured mass due to Fmag is determined by the Lorentz force, and Newton's third law ensures the total measured mass of the magnets doesn't change.
Step-by-step explanation:
The mass change you're inquiring about due to the magnetic force (Fmag) is the result of the Lorentz force exerted on a current-carrying conductor in a magnetic field. Using the formula F = ILB sin(θ) where I is the current, L is the length of the conductor, B is the magnetic field, and θ is the angle between the conductor and the magnetic field, we can determine the magnitude of the force. Since the current goes from East to West and the magnetic field from North to South, the angle θ is 90 degrees, making sin(θ) = 1. Assuming the conductor's weight is already factored into the initial mass measured, the magnetic force will either increase or decrease the measured mass depending on the direction of the current relative to the magnetic field. According to Newton's third law, the force exerted on the magnet by the wire (action) is equal and opposite to the force exerted on the wire by the magnet (reaction), so the measured mass remains unchanged because both forces cancel each other out.