A boat is floating in the water. If it sinks, will the water level rise or fall?

When considering whether the water level will rise or fall if a floating boat sinks, it's important to understand the principles of buoyancy and displacement. A floating boat displaces a volume of water that is equivalent to the weight of the boat itself.

While the boat is floating, it pushes aside a certain amount of water, causing the water level to rise. If the boat sinks, it will displace an amount of water equal to its own volume, not its weight. Typically, the volume of water displaced when the boat is floating (which is based on its weight) will be greater than the volume of water it displaces once it sinks, since the boat, once submerged, is displacing water only based on its own size and not its weight.

As a result, when the boat sinks, it stops displacing that greater volume of water, and the overall level of the water falls. This economic and physical reasoning aligns with the principle of buoyancy and is why the answer is that the water level will fall when the boat sinks. The understanding hinges on distinguishing between the two different states of displacement: when the boat is floating compared to when it is submerged.