A rectangular loop of wire with sides 0.23 and 0.39 m lies in a plane perpendicular to a constant magnetic field (see part a of the drawing). The magnetic field has a magnitude of 0.60 T and is directed parallel to the normal of the loop's surface. In a time of 0.17 s, one half of the loop is then folded back onto the other half, as indicated in part b of the drawing. Determine the magnitude of the average emf induced in the loop.