# Why does a baseball sink but a plastic ball floats?

Have you ever wondered why a baseball sinks but a plastic ball floats? It’s an interesting question that has been asked by many people for a long time. This article will discuss why a baseball sinks but a plastic ball floats, providing an overview of the scientific, physical, and chemical properties that are involved.

## The Science Behind Sinking and Floating

The scientific principle behind sinking and floating is known as buoyancy. Buoyancy is the ability of an object to float in a liquid or gas. The buoyancy of an object is determined by a few factors: the mass of the object, the density of the object, and the density of the liquid or gas it is floating in.

When an object is placed in a liquid or gas, it will either sink or float depending on its density. If the object has a lower density than the liquid or gas, it will float. If the object has a higher density than the liquid or gas, it will sink.

## The Physical Properties of Baseballs and Plastic Balls

The physical properties of a baseball and a plastic ball are one of the factors that determine whether or not they will sink or float. A baseball is made of a rubber core, a leather cover, and a layer of yarn. The yarn is wound tightly around the core and the leather cover is sewn on. The physical properties of a baseball are determined by its composition and structure.

A plastic ball is made of a polyurethane or polyvinyl chloride (PVC) shell, filled with a gas, such as helium or nitrogen. The physical properties of a plastic ball are determined by its composition and the gas it is filled with.

## The Density of Baseballs and Plastic Balls

The density of an object is the mass of the object divided by its volume. The density of a baseball is 1.42 g/cm3, while the density of a plastic ball is 0.98 g/cm3. The lower density of a plastic ball compared to a baseball is what makes it float in water.

## The Buoyancy of Baseballs and Plastic Balls

The buoyancy of an object is determined by its density in relation to the density of the liquid or gas it is floating in. Water has a density of 1 g/cm3, which is greater than the density of a baseball, but lower than the density of a plastic ball. This means that a baseball is more dense than water, so it will sink, while a plastic ball is less dense than water, so it will float.

## The Surface Tension of Baseballs and Plastic Balls

Another factor that affects the sinking or floating of an object is surface tension. Surface tension is the attraction of the molecules of a liquid or gas to each other. This attraction causes the surface of the liquid or gas to become more rigid, which can affect the sinking or floating of an object.

A baseball has a smooth surface, while a plastic ball has a rough surface. The smooth surface of a baseball allows the molecules of the liquid or gas it is floating in to easily attach to it, thus increasing its density and causing it to sink. The rough surface of a plastic ball prevents the molecules of the liquid or gas from attaching to it, thus decreasing its density and causing it to float.

## The Size of Baseballs and Plastic Balls

The size of an object is also a factor that can affect its ability to sink or float. A larger object has more mass and will be more likely to sink, while a smaller object has less mass and will be more likely to float. A baseball is much larger than a plastic ball, so it has more mass and is more likely to sink.

## The Shape of Baseballs and Plastic Balls

The shape of an object can also affect its ability to sink or float. An object with a rounded shape, such as a sphere, will be more likely to float because it has less surface area exposed to the liquid or gas it is floating in. A baseball has a rounded shape, while a plastic ball is usually a sphere, so the plastic ball is more likely to float.

## The Weight of Baseballs and Plastic Balls

The weight of an object is also a factor that can affect its ability to sink or float. A heavier object has more mass and will be more likely to sink, while a lighter object has less mass and will be more likely to float. A baseball is much heavier than a plastic ball, so it is more likely to sink.

## Conclusion

To conclude, a baseball sinks but a plastic ball floats because of the scientific, physical, and chemical properties of the two objects. The density of a baseball is greater than the density of the liquid or gas it is floating in, so it sinks. The density of a plastic ball is lower than the density of the liquid or gas it is floating in, so it floats. The physical properties of the two objects, such as their composition, structure, size, shape, and weight, also affect their ability to sink or float.

In summary, the scientific principle of buoyancy and the physical and chemical properties of a baseball and a plastic ball are what determine whether or not they will sink or float.