The figure shows a zero-resistance rod sliding to the right on two zero-resistance rails separated by the distance L = 0.450m. The rails are connected by a 12.5 ohm resistor, and the entire system is in a uniform magnetic field with a magnitude of 0.750 T.

a) Find the speed at which the bar must be moved to produce a current of 0.155 A in the resistor.

b) Find the force that must be exerted on the rod to maintain a constant current of 0.155 A in the resistor

c) What is the rate of energy dissipation in the resistor?

d) What is the mechanical power delivered to the rod?