I'm doing a lab write-up for physics 2. The experiment is about the title, a bar magnet being dropped through a solenoid. I have to explain four graphs that plot the change in emf (y axis) vs. time (x) axis. There are incoming and outgoing peaks on these graphs. I have to tie these results with the equation emf = -N(ΔΦ/Δt). For example, if a bar magnet is dropped with north facing downward through the center of the coil, why is the incoming peak positive? How do the magnetic field, induced magnetic field, and emf all tie together to produce a positive peak? Thanks!