30. Consider the arrangement shown in Figure P20.30 where R = 6.00 0, / = 1.20 m, and B = 2.50 T. a. At what constant speed should the bar be moved to produce a current of 1.00 A in the resistor? b. What power is delivered to the resistor? c. What magnetic force is exerted on the moving bar? d. What instantaneous power is delivered by the force Fapp on the moving bar? Figure P20.30 Problems 30, Problems 56, and Problems 59. X X R # F