In the figure a metal wire of mass m 231 mg can slide with

In the figure, a metal wire of mass m = 23.1 mg can slide with negligible friction on two horizontal parallel rails separated by distance d = 3.99 cm. The track lies in a vertical uniform magnetic field of magnitude 65.4 mT. At time f = 0 s, device 6 is connected to the rails, producing a constant current i = 7.83 mA in the wire and rails (even as the wire moves). At f = 71.1 ms, what are the wire\'s (a) speed and (b) direction of motion? (a) Number Units (b)

Solution

F = i L B = i d B sin 90 = i d B

F = m a, a = F / m

v = a t = i d B t / m

v = (7.83 * 10^-3 * 3.99 * 10^-2 * 65.4 * 10^-3 * 71.1 * 10^-3) / (2.31 * 10^-5)

v = 6.29 * 10^-2 m/s

= left