Floats

A wooden block floats in a sealed container. What happens to the block when gas is injected above the water?

I just need to know if it floats lower or higher in the water. Thanks.

Public Comments

1. The wooden block holds it's nose closed.
2. depends what gas you put in, the heavier the gas, it will lower the block.
3. lower
4. lower
5. then you throw a match in the containter and BOOM!!!
6. All wrong above. It stays the same. A floating object displaces its weight in water, period. You could evacuate or pressurize the container -- it wouldn't affect the block. BTW, a submerged object displaces its volume. A good variant of this question is: "A block of ice is floating in a tub partially filled with water; when the ice melts, what happens to the water level?"
7. Depends on the gas. If you inject, say, helium or hydrogen the gas might buoy up the block because the gas is lighter than the surrounding air (although since you only injected gas and did not release any the sealed container would technically weigh more). If you inject something very heavy, like Argon, it will sink lower. -Neb
8. it's very simple. Originally, the block floats at a stable level because the pressure pushing it upwards (generated by the water which is more dense) is equal to the pressure pushing it downwards (gravity and the pressure of the atmosphere above it). If you add gas to the sealed container, then the pressure of the atmosphere above it will increase. To counteract this increased pressure, the block will float LOWER in the water until the pressure pushing it up is, again, equal to the new, higher pressure pushing it down. So the answer is it will float lower because there is more pressure to push it down now - gravity has stayed the same but atmospheric pressure has increased.
9. You have a lot of different answers. The reason they are different is that we are missing several vital pieces of data. What is in the sealed container (besides water and block) initially, and is the container filled. What gas is injected and how much. Case 1) container is totally filled with water and the block. In this case the question is meaningless as the block is not floating. Case 2) container is half filled with water, and nothing else. The void will get quickly filled with water vapor, and the block will be floating in the water. Exact pressure of the water vapor would have to be calculated. Case 3) ... but why go on...
10. You are in physics 1210 @ Mizzou arent you? I googled this phrase and this popped up...i agree with most of the above though, that it goes lower.