Beakman challenge: use a hammer to break a ruler without holding the ruler. When Lester tries the first time, the ruler flips off the table. Beakman lays two pieces of newspaper on the end of the ruler and now the ruler breaks. Beakman explains this is because of air resistance. Without the paper, the ruler didn't have much to resist but with the paper, it has to push that paper away too and since you hit it so fast with the hammer, it doesn't have time and it breaks.