9. Which of the following does not contribute to the potential energy of an object? height of the object above the Earth's surface gravitational constant or g of the Earth velocity of the object mass of the object

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?