WHY EGG FLOATS IN SALT WATER

Have you ever wondered why an egg floats in salt water but sinks in fresh water? This is a common science experiment that can be easily done at home, and it’s a great way to learn about the principles of buoyancy and density.

The Science Behind It

Buoyancy is the upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In other words, it’s what keeps an object from sinking. The amount of buoyancy an object experiences is equal to the weight of the fluid displaced by the object.

Density is the measure of how much mass an object has for a given volume. The denser an object is, the more mass it has for its size. Denser objects sink in water because they displace less water than less dense objects.

In the case of an egg, the egg white is denser than the egg yolk. This means that the egg white displaces less water than the egg yolk. When an egg is placed in fresh water, the denser egg white sinks to the bottom and the less dense egg yolk rises to the top. This causes the egg to stand upright.

When an egg is placed in salt water, the salt dissolves in the water and increases the density of the water. This means that the egg white is now displaced by more water than it was in fresh water. This causes the egg to float.

The Experiment

To see this for yourself, you can try the following experiment.

1. Fill two glasses with water. One glass should be filled with fresh water and the other glass should be filled with salt water.
2. Gently place an egg in each glass.
3. Observe what happens.

In the glass with fresh water, the egg will sink to the bottom. In the glass with salt water, the egg will float.

Applications of Buoyancy

The principles of buoyancy are used in a variety of applications, including:

• Ships: Ships float because they displace a large amount of water. The weight of the water that is displaced is greater than the weight of the ship, so the ship floats.
• Submarines: Submarines can sink and float by changing their buoyancy. When a submarine wants to sink, it takes in water to increase its density. When a submarine wants to float, it pumps out the water to decrease its density.
• Hot Air Balloons: Hot air balloons float because the hot air inside the balloon is less dense than the cold air outside the balloon. The weight of the air that is displaced by the balloon is greater than the weight of the balloon, so the balloon floats.

Conclusion

Buoyancy is a fundamental principle of physics that has a wide range of applications. By understanding the principles of buoyancy, we can design and build objects that float, such as ships, submarines, and hot air balloons.

FAQs

1. Why do some objects float and others sink?

Objects float if they are less dense than the fluid they are placed in. Objects sink if they are denser than the fluid they are placed in.

2. What is the relationship between buoyancy and density?

Buoyancy is the upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. Density is the measure of how much mass an object has for a given volume. The denser an object is, the more mass it has for its size. Denser objects sink in water because they displace less water than less dense objects.

3. How can you make an object float?

You can make an object float by decreasing its density. This can be done by adding air or foam to the object, or by dissolving a salt or other substance in the fluid.

4. What are some applications of buoyancy?

The principles of buoyancy are used in a variety of applications, including ships, submarines, and hot air balloons.

5. What is the experiment to show that an egg floats in salt water?

Fill two glasses with water. One glass should be filled with fresh water and the other glass should be filled with salt water. Gently place an egg in each glass. Observe what happens. In the glass with fresh water, the egg will sink to the bottom. In the glass with salt water, the egg will float.