Here's a Question! - Boat and Anchor (Part 3)
A boat floats calmly in a partly filled aquarium. The boat's anchor is thrown overboard but, due to shoddy construction techniques, it does not reach 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. But, due to shoddy construction techniques... Steve... The rope attached to the anchor is too short for the anchor 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.
What happens to the level of the water if the anchor doesn't reach the bottom of the aquarium?
The level stays the same.
Steve: The boat floats because it displaces a volume of water with a weight that's equal to the weight of the boat.
Joanna: Since the anchor doesn't come to rest on the bottom of the aquarium, the total weight that's floating doesn't change.
Steve: If the amount of weight that's floating doesn't change, then the amount of water that's displaced doesn't change. The water level stays the same.
Joanna: Thanks for watching. I hope you'll join us again soon for another question!
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