A group of elementary students were playing shuffle board on the playground. One student pushed the puck toward the opposite side of the game board. The student thought the puck would continue all the way to the other side, but the puck stopped half-way down the board. Explain in terms of force why the puck failed to slide all the way to the opposite side of the board.

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?