Archimedes’ principle

Archimedes' Principle

Archimedes' principle states that when an object is partially or totally immersed in a fluid, it experiences an upthrust which is equal to the weight of the fluid displaced by the object.

Demonstration of Archimedes' Principle

Key Points of Archimedes' Principle

1. When an object is submerged in a fluid, it feels an upthrust or buoyant force that acts in the opposite direction to its weight.
2. The magnitude of this upthrust is equal to the weight of the fluid that the object displaces.
3. Archimedes' principle applies to both solid and liquid objects that are immersed in fluids.

Example

Consider a stone with a weight of 100 N when it is in the air. If the stone is immersed in water, it weighs 80 N due to the buoyant force acting on it.

To calculate the upthrust or buoyant force:

Formula: Upthrust = Weight of the object in the air - Weight of the object in the fluid

Calculation: Upthrust = 100 N (weight in air) - 80 N (weight in fluid) Upthrust = 20 N

Thus, the upthrust force acting on the stone is 20 N.

This principle helps explain why objects float or sink. If the upthrust is greater than the object's weight, it will float. If the weight is greater, the object will sink.