A magnetized sewing needle has a magnetic moment of 12.48 mA · m2. At its location, the Earth's magnetic field is 57.7 µT northward at 48.0° below the horizontal.
(a) Identify the orientation of the needle that represent the minimum potential energy.
north at 48.0° below the horizontal
north at 48.0° above the horizontal
south at 48.0° below the horizontal
south at 48.0° above the horizontal
(b) Identify the orientation of the needle that represent the maximum potential energy of the needle-field system.
north at 48.0° below the horizontal
north at 48.0° above the horizontal
south at 48.0° below the horizontal
south at 48.0° above the horizontal
(c) How much work must be done on the system to move the needle from the minimum to the maximum potential energy orientation?