Question
(a) A pendulum is set up so that its bob (a thin copper disk) swings between the poles of a permanent magnet as shown in Figure 22.69. What is the magnitude and direction of the magnetic force on the bob at the lowest point in its path, if it has a positive $0.250 \mu\textrm{C}$ charge and is released from a height of 30.0 cm above its lowest point? The magnetic field strength is 1.50 T. (b) What is the acceleration of the bob at the bottom of its swing if its mass is 30.0 grams and it is hung from a flexible string? Be certain to include a free-body diagram as part of your analysis.
Question Image
1. $9.09 \times 10^{-7} \textrm{ N, directed up}$
2. $3.03 \times 10^{-5} \textrm{ m/s}^2 \textrm{ , up}$
Solution Video