In Dr. Leila's article on March 25, she suggested an experiment to see which would roll down a ramp faster: a frozen can of fruit cocktail or an unfrozen one. Kids tried it in the classroom and at home, and what they found was that almost all of the time, the frozen can of fruit cocktail would beat the unfrozen one hands down.

Now why is that? Well, if you read Dr. Leila's April 8th article, you might guess that it has something to do with angular momentum and rotational inertia.

When a frozen can of fruit cocktail rolls down a ramp, the fruit inside can't move around very much at all. On the other hand, when an unfrozen can of fruit cocktail rolls down a ramp, maybe what happens is that the fruit inside gets pushed out against the wall of the can. With the fruit all spread out, the rotational inertia is greater, resulting in a slower speed down the ramp.

But does the fruit really end up against the wall of the can when it rolls? We simulated this by spinning some jelly beans in a bottle on a record player. Take a look for yourself:

Do you agree with this explanation for the rolling can experiment? Do you think our jelly bean set-up is a good simulation for a rolling fruit cocktail can?