Perhaps the most famous experiment in physics is Galileo's effort to demonstrate that the rate of falling of a body is independent of its mass by dropping objects from the top of the leaning tower of Pisa. Galileo might not have actually ever done the experiment but it's a core part of the story of the history of physics.
Science writer Dan Falk attended physicist Steve Shore's re-creation of the event at the tower and made the video below. He warned me that he gives a simplified explanation of the effects of air resistance; because of the link between the speed of a object and the amount of air resistance, a bowling ball would fall faster than a volleyball, contrary to what Dan suggests in his narration--but the thrust of the argument is OK.
So what will happen in real world conditions? Does the effect of mass cancel out as it would if there were no air resistance? Or does the way that the force of air resistance has a different dependence on mass to the force due to gravity mean that the heavier objects will fall faster? And what would happen when the objects are identical in shape but with different masses? In his experiment, Shore used bottles of different sizes, filled with water.
Make a prediction about the results before you watch the video. Whatever you predict, you know you'll see a big splat at the end!
