6. N electrons move at speed v in a circular orbit of radius R. What is the magnetic dipole moment associated with the current loop?_(6)_

10. Several objects (a hoop, a solid cylinder, a solid sphere, and a thin spherical shell) roll, without slipping down an incline of vertical height H, all starting from rest at the same moment. In addition a box slides down without friction. In what order do they reach the bottom of the incline?