In the figure below, an iron bar sitting on two parallel copper rails, connected to each other by a resistor, is pulled to the right with a constant force of magnitude Fapp = 1.45 N. The friction between the bar and rails is negligible. The resistance R = 8.00 O, the bar is moving at a constant speed of 1.85 m/s, the distance between the rails is f, and a uniform magnetic field E is directed into the page. g]? l > ' (D (a) What is the current through the resistor (in A)? :A (b) If the magnituce of the magnetic field is 2.90 T, what is the length f (in m)? :m (c) What is the rate at which energy is delivered to the resistor (in W)? :W (d) What is the mechanical power delivered by the applied constant force (in W)? :W What If? Suppose the magnetic field has an initial value of 2.90 T at time t = 0 and increases at a constant rate of 0.500 T/s. The bar starts at an initial position x0 = 0.100 m to the right of the resistor at t = 0, and again moves at a constant speed of 1.85 m/s. Derive time-varying expressions for the following quantities. (e) the current through the 8.00 O resistor R (Use the following as necessary: t. Assume I(t) is in A and t is in s. Do not include units in your answer.) I(t) = A (f) the magnitude of the applied force Fapp required to keep the bar moving at a constant speed (Use the following as necessary: t. Assume F appU') is in N and t is in 5. Do not include units in your answer.) FaPPU') = N