What is the Archimedes’ Principle? | Gravitation | Physics | Infinity Learn

Summary

This video explains Archimedes' principle, which states that the buoyant force on an object submerged in a fluid equals the weight of the fluid displaced by the object. The script demonstrates this through examples, such as a solid object in water and the floating of steel ships. It also highlights how the water level rises when objects are submerged, illustrating the displacement effect. The concept of relative density is introduced at the end, with a promise to cover it in more detail in the next lesson. This video provides a clear, accessible understanding of buoyancy and Archimedes' principle.

Takeaways

• 😀 The water level rises when an object is immersed in it, demonstrating the concept of displacement.
• 😀 Archimedes' principle states that the buoyant force on an object is equal to the weight of the fluid displaced.
• 😀 The more of an object that is submerged, the more water is displaced, and the higher the buoyant force.
• 😀 When a person enters a bathtub, the water level rises, indicating that the person's body displaces water.
• 😀 An object in a fluid experiences an upward buoyant force, which acts in opposition to the weight of the object.
• 😀 The buoyant force on an object can be measured using a spring balance, which will show a lower weight when the object is submerged in water.
• 😀 The weight of the displaced fluid is directly linked to the buoyant force acting on the object.
• 😀 Archimedes' principle applies to both fully and partially submerged objects, regardless of their shape.
• 😀 Steel ships float because the weight of the displaced water equals the weight of the ship, allowing it to stay afloat.
• 😀 The principle of buoyancy is critical to understanding how large objects like ships can float on water.

Q & A

What happens to the water level when an object is placed in it?

When an object is placed in water, the water level rises because the object displaces a certain volume of water. The more submerged the object is, the greater the displacement and rise in water level.

What principle did Archimedes discover related to displaced water?

Archimedes discovered that the buoyant force exerted by a fluid on an object submerged in it is equal to the weight of the fluid displaced by the object.

How does the buoyant force relate to the weight of displaced water?

The buoyant force on an object submerged in a fluid is directly equal to the weight of the fluid that the object displaces. This is the core idea behind Archimedes' principle.

What happens to the weight reading of an object when submerged in water?

When an object is submerged in water, the weight reading on a spring balance decreases because the buoyant force acts upward, counteracting the object's weight.

How can you observe Archimedes' principle using a spring balance?

By suspending an object from a spring balance and gradually submerging it in water, you can observe that the weight reading decreases due to the upward buoyant force, which is equal to the weight of the displaced water.

Why do large steel ships float despite being made of metal?

Steel ships float because they displace enough water to create a buoyant force that equals their weight. The shape of the ship ensures that it displaces a large volume of water, making the buoyant force sufficient to keep it afloat.

What is the relationship between the buoyant force and the weight of a steel ship?

The buoyant force acting on a steel ship is equal to the weight of the water displaced by the ship. If this displaced water's weight is greater than or equal to the ship's weight, the ship will float.

What does Archimedes' principle say about the upward force applied by a fluid on an object?

Archimedes' principle states that the upward force applied by a fluid on an object submerged in it is equal to the weight of the fluid displaced by the object, regardless of the object's shape or density.

What happens when an object displaces water in terms of mass?

When an object displaces water, it causes the water to increase in volume, which results in the displacement of the mass of water equal to the weight of the object submerged.

What is relative density and how does it relate to buoyancy?

Relative density refers to the ratio of the density of an object to the density of a fluid (usually water). It helps determine whether an object will sink or float. Objects with lower relative density than water will float, while those with higher density will sink.