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How do boats float?

The buoyant force is a little mysterious in how it works. Looking at some of the ginormous boats that carry hundreds of passengers, logically that boat should not stay above the water. However, a simple understanding of density answers all of these mysteries.

Density is the amount of mass per volume. When you look at an anchor, a lot of mass takes up a small volume. The anchor is very dense, even more than the water. Because the anchor has more mass in an amount of volume than water, it will sink. When a large cruise ship is considered, it would make sense that because it has so much mass, it would sink. This doesn’t happen, though, because cruise ships are filled with a lot of air. All of this air lowers the density as the mass of the ship then takes up more space. If the same amount of volume is considered with water and with the ship, the ship actually has less mass. This means that it is less dense, and will therefore float.

This difference in density is described as the buoyant force that pushes up on the boat and keeps it from sinking. This force also directly opposes the gravitational force in both direction and magnitude. The reasoning for buoyant force in this situation also holds for all of the other scenarios discussed later.

Other Scenarios - Floating Boat (  please click me!)