Shall we find out if buoyancy does anything to heavy stuff that wouldn't float anyway? How can it, if it is something we can't expect to float?

We'll fill our one-pound coffee can with water and put on its plastic lid. Strong twine can be looped around it, with a tail of about two feet long, for a handle.

Now, take turns lifting the can by its tail, from the ground, up and over to the large pail of water waiting nearby. Lower the can, by its tail, into the water. Lift it out of the water and feel the weight of the can. Now put it back into the water and feel the weight of the can.

Somehow, it seems lighter when it is in the water, doesn't it? Do you know why that is? It is buoyancy.

Buoyancy has a lot of tricks!