Ametal ring of radius a and mass m falls into a constant and uniform gravitational field, with the acceleration g, inside a magnetic field, in which the vertical component bz depends on z. the plane of the ring remains horizontal and the resistance of the ring is r. if the inductance of the ring is negligible, prove that for a long fall, the ring's velocity becomes independent of z if (dbz/dz) → b1 for large |z|, where b1 is a constant. find this constant limiting velocity. find the velocity at all times for the case bz = b0 + b1z, where b0 and b1 are constants.