Here's a Question!

Announcer: Frostbite Theater presents... Cold Cuts! No baloney!

Joanna and Steve: Just science!

Joanna: Hi! I'm Joanna!

Steve: And I'm Steve!

Joanna: Here's a question for you...

Steve: A boat of dubious construction floats calmly in a partly filled aquarium.

Joanna: The boat's anchor is thrown overboard and comes to rest on the bottom of the aquarium.

Steve: What happens to the level of the water?

Joanna: Does the level rise?

Steve: Does the level fall?

Joanna: Does the level stay the same?

Steve: Or, does it depend on how deep the water is?

Joanna: Pause the video now if you'd like to think it over before we show you what happens.

Steve: What happens to the level of the water when the anchor is thrown overboard?

The level falls.

Joanna: The boat floats because it displaces a volume of water with a weight that's equal to the weight of the boat.

Steve: Once the anchor is thrown overboard, its weight is no longer floating.

Joanna: The lighter boat displaces less water while its anchor only displaces its volume in water, not its weight.

Steve: The net result - the water level falls.

Joanna: Thanks for watching. I hope you'll join us again soon for another question!