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7. [4/6 Points] PREVIOUS ANSWERS SERPSE10 30.2.OP.016. In the figure below, a steel bar sitting on two parallel metal rails, connected to each other by a resistor, is pulled to the right with a constant force of magnitude Fapp 1.20 N. The friction between the bar and rails is negligible. The resistance R = 8.000, the bar is moving at a constant speed of 1.95 m/s, the distance between the rails is f, and a uniform magnetic field B is directed into the page. DETAILS IE F.... @ (a) What is the current through the resistor (in A)? 54 (b) If the magnitude of the magnetic field is 2.50 T, what is the length (in m)? 88752 ✔m (c) What is the rate at which energy is delivered to the resistor (in W)? 2.34 (d) What is the mechanical power delivered by the applied constant force (in W)? 2.34 ✓ W A Need Help? Read It MY NOTES What If? Suppose the magnetic field has an initial value of 2.50 T at time t= 0 and increases at a constant rate of 0.500 T/s. The bar starts at an initial position x 0.100 m to the right of the resistor at t=0, and again moves at a constant speed of 1.95 m/s. Derive time-varying expressions for the following quantities. (e) the current through the 8.000 resistor R (Use the following as necessary: t. Assume (2) is in A and 2 is in s. Da not include units in your answer.) I() = ASK YOUR TEACHER (r) the magnitude of the applied force Fapp required to keep the bar moving at a constant speed (Use the following as necessary: t. Assume Fapo(t) is in N and is in s. Do not include units in your answer.) Fapp(t) = N PRACTICE ANOTHER