An astronaut is connected to her spacecraft by a 25 meter long tether cord as she and the spacecraft orbit Earth in a circular path at a speed of 3.0 x 10^3 m/s. At one instant, the voltage measured between the ends of a wire embedded in the cord is measured to be 0.45 Volt. Suppose the longer dimension of the cord is perpendicular to the vertical component of Earth's magnetic field at that instant.
(a) Find the magnitude of the vertical component of Earth's field at this location?
(b) Does the measured voltage change as the system moves from one location to another? Explain.