Physics Brain Teaser?!
Question:
Physics Brain Teaser?
You can read great brain teasers at http://www.mindchallenger.com Try and solve this without looking for the answer:
A boat loaded with a rock is floating in a pool. The rock is cast over and it sinks to the bottom. What happens to the water level of the pool? It goes up, down, or stays the same? Why?
Answers: it will...
uhh..
it will go down because the rock has to be smaller than the boat, and the boat is floating, so the part of the boat still in the water will probably be smaller than the rock
yes im so smart, arent i My guess would be that the water level stays the same due to the fact that the boat is being displaced downward in the water by the weight of the rock already. When the rock falls in, the boat will raise up, but the water level will be the same because the rock is now in the water. Without looking, I say that it stays the same since the water level has already been displaced by the rock since it was in a boat that was on the the water. ;) I'd say the water level stays the same, because just one rock isn't enough weight to make a big difference. Besides that, it's the same amount of weight in the pool as there was whenever it started off; the only difference is that the rock is now in the pool. The boat is still there, and the rock is still there ... regardless of what position they are in. It's not like anything else was added or taken away ... Perhaps the water level goes up, because the rock was not displacing water while it was in the boat, only it's weight might have pushed the boat down further, that is not the rock's displacement size.
Can this be tested? How about a bb in a bottle cap in glass of water? Hmmm... it goes up stays the same.... same levle because your not taking put mass our putting it in ;)