3. You are conducting a magnetic survey in Minnesota with a proton-precession magnetometer with a sensitivity of 1 nT. Make some simplifying assumptions (e.g. I=90°) and estimate how far away from the magnetic senor you need to be from a 2000-pound (=1 ton) car (on the surface) so that the magnetic signal is less than 1 nT? The magnetic moment for typical iron and steel objects is 100 Am?/ton.

3. You are conducting a magnetic survey in Minnesota with a proton-precession magnetometer with a sensitivity of 1 nT. Make some simplifying assumptions (e.g. I=90°) and estimate how far away from the magnetic senor you need to be from a 2000-pound (=1 ton) car (on the surface) so that the magnetic signal is less than 1 nT? The magnetic moment for typical iron and steel objects is 100 Am?/ton.