Here's a Question! - Boat and Anchor (Part 1)
A boat floats calmly in a partly filled aquarium. The boat's anchor is thrown overboard and comes to rest on the bottom of the aquarium. What happens to the level of the water?
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!
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