E) Now consider the circuit shown. A metal bar rests on top of two wires such that there is a good electrical contact between the ends of the bar and the wire. The wires are connected to a battery and switch as shown. The whole circuit is in a constant magnetic field B out of the page. You can assume the total resistance in the circuit, independent of the position of the bar, is a constant R and any friction between the bar and the wires is negligible. O (out) When the switch is first closed, there will be a current through the bar due to the battery. What is the direction of the magnetic force on the bar? Explain your answer. (This is the basic physics for the operation of a "Rail Gun".) F) As the bar moves due to the force from Part E, an induced EMF will be created in the bar. What direction will this EMF be? (In other words, what direction will this EMF cause an induced current to flow, CW or CCW?) Explain. G) Solve for an equation for the induced EMF (EMF due to Faraday's Law) in terms of the B , W, and v (the speed of the bar). (You can consider this EMF to be "in the bar"). What happens to the total EMF in the circuit (Induced EMF plus AV ) in the circuit? H) Describe what will happen to the current in the circuit and the velocity of the bar as a function of time. Start at the time the switch is closed and consider what happens for a long time afterwards. Assume the bar stays in the magnetic field and on the wire. Be sure to explain your answer. Hint: What is the magnetic force on the bar if the total EMF in the circuit is zero? 1) If the largest magnetic field you can create is B = 0.25 7, the resistance of the circuit is R = 1.5 0, and the width of your wire circuit is W = 0. 10 m, what battery voltage, AV , do you need to apply to the circuit for your bar to have a maximum possible speed of 100 m/s, again assuming it stays in the field and on the wire