A small bar magnet of mass 0.1 kg, length 1 cm, and magnetic moment = 0.04

A small bar magnet of mass 0.1 kg, length 1 cm, and magnetic moment μ = 0.04 A · m² is located at the center of a 100-turn loop of 0.2 m diameter. The loop carries a current of 5.0 A. At equilibrium, the bar magnet is aligned with the field due to the current loop. The bar magnet is given a displacement along the axis of the loop and released. Show that if the displacement is small, the bar magnet executes simple harmonic motion, and find the period of this motion.