I introduced terminal velocity yesterday. Most students had no idea what it was. They had a lot of misconceptions (penny off the Empire State Building will kill you). Today we had short periods so we had time for the Mythbusters Penny Drop video and a quick analysis of a distance-time graph and a velocity-time graph for a falling coffee filter. The graphs showed beautifully that the filter accelerated for less than a second (as seen by the curved d-t graph and the corresponding straight line on the v-t graph) before reaching a terminal velocity of about -0.55 m/s (shown by the straight line with (-) slope on the d-t graph and the horizontal line on the v-t graph). Tomorrow they do their own investigation with coffee filters.