in fig. 30-45, two straight conducting rails form a right angle. a conducting bar in contact with the rails starts at the vertex at time t 0 and moves with a constant velocity of 5.20 m/s along them. a magnetic field with b 0.350 t is directed out of the page. calculate (a) the flux through the triangle formed by the rails and bar at t 3.00 s and (b) the emf around the triangle at that time. (c) if the emf is at n, where a and n are constants, what is the value of n?