A yacht on a lake drops its anchor overboard. What happens to the water level in the lake?
- It rises very slightly.
- It falls very slightly.
- It stays exactly the same.
- It's impossible to say.
My understanding is that due to Archimedes principle, when the anchor is in the boat, it contributes to the mass of the boat, and thus the mass of water displaced. When it is thrown overboard, it is now the volume of the anchor which contributes to the amount of water displaced. Therefore, without knowing the density, mass and volume of the anchor, it is impossible to determine the effect on the water level, therefore the correct answer is option 4.
Can anyone tell me if my reasoning is correct as there is no mark scheme for the test where this question came from.
Thanks in advance!