Fred swings a sheet of copper in pendulum fashion between the poles of a strong magnet. The sheet slows in entering the magnetic field because it
A. induces swirling currents in the copper and accompanying magnetic fields that resist motion.
B. experiences both air and magnetic friction.
C. is repelled by free electrons in the copper.
D. none of the above
Answer:A
Fred swings a sheet of copper in pendulum fashion between the poles of a strong magnet. The sheet slows in entering the magnetic field because it
A. induces swirling currents in the copper and accompanying magnetic fields that resist motion. B. experiences both air and magnetic friction. C. is repelled by free electrons in the copper. D. none of the above