(A) A 40-cm long massless bar with resistance 0.12 2 is pulled upward on zero-resistance rails at a constant speed of 15 cm/s, as shown below. The circuit is surrounded by a uniform magnetic field of magnitude 1.6 T directed out of the page.
(a) Using Faraday's Law, calculate the magnitude of the induced current in the circuit. (Note: You must show all your work; simply plugging numbers into a result derived in class is not enough!)
(b) Using Lenz's Law and stating your reasoning, determine the general direction of the induced current in the circuit, as well as the specific direction of the induced current in the bar.
(c) Find the magnitude of the applied force required to pull the massless bar upward at constant speed. Explain whether the magnitude of the magnetic force on the bar would increase, decrease, or remain unchanged if the bar were not massless (assuming it is still pulled upward at constant speed)
