When The Greek Said ," Eureka, Eureka"!!! - Archimedes.

All about Archimedes and his principle :

Where it all Started... Story Telling

Archimedes was a great mathematician born in Syracuse, Sicily, Italy in 287 BC. He was an outstanding ancient Greek mathematician. Archimedes has travelled to  Egypt for his formal education. Upon completing his studies, he came back to Syracuse to help with his family and to work for King Hiero II as an engineer. His fame came from his relationship with King Hiero. He spent most of his time trying to solve problems for the king. His most popular solution was in regards to the golden crown. King was worried that the goldsmith who was making the crown was replacing some of the gold with another metal. He called upon Archimedes to find a way to see if the crown was made of pure gold or some metal also has been used. Archimedes came upon the solution on how to prove this as he was taking a bath. After entering a full tub of water, he noticed that the weight of his body displaced a certain amount of water. Knowing that the same principle could be used on the crown, he forgot himself with excitement. He jumped out of the tub and ran without clothes through the town, yelling ‘Eureka, Eureka’. He died at the age of 75.

As the Books Quote :

Archimedes’ principle:

He discovered the physical law of buoyancy, which is known as Archimedes’ principle. It states that anybody completely or partially deluged in a fluid at rest is acted upon by an upward or buoyant force. The magnitude of the force is equivalent to the weight of the displaced fluid. The volume of displaced fluid is equal to the volume of an object submerged in a fluid or to that small section of the volume below the surface for an object partially immersed in a liquid.

ok ok Lets make it bit simple...

Archimedes' principle deals with the forces applied to objects by the fluids around that object. This applied force reduces the net weight of any object in a fluid, whether it be a liquid or a gas.

What is Archimedes' Principle?

Have you ever heard someone say, 'Whatever floats your boat'? Well, the answer should always be 'buoyancy.'

Buoyant force is the force applied upward on an object by any fluid. Archimedes' principle states that the buoyant force applied to an object is equal to the weight of the fluid the object displaces.

Lets Take A Closer Look

Let's take a closer look at this definition. First, we need to understand 'displacement.'

As the story goes, Archimedes poured himself a warm bath one day, and when he got in, he realized the level of the water went up. He then determined that the more of his body he put in the bath, the higher the water level went.

This means the volume of his body that he put in the water had to move or (displace) the water so he could fit in the bath. Therefore, displacement in this context is when an object moves a fluid so it can occupy the volume the fluid originally occupied.

Everything Gets Better with Examples.. So Lets Hit some Examples to better Understand What Greek Meant.

Example - The Battleship

Let's use a battleship as an example. A battleship is made of steel. Right about now, you may be saying, 'But steel doesn't float!' So how is it a battleship can float?

Look at the image of the battleship. Now imagine drawing a line where the water comes up on the hull of the ship. Then, fill the ship's hull with water up to that line. How much do you think the water would weigh? If you said 'a lot,' you're right. It would actually weigh as much as the entire ship!

The weight of the water to fill up the hull of the ship weighs the same as the ship, so the water applies a buoyant force up on the ship with this much force. Therefore, the ship made of steel floats!

                 

Example - Ice Cube

Let's look at another example. If you put an ice cube in a glass of water, the cube floats because ice is less dense than water. So, the ice underwater displaces that volume of water.

To make things easy, we will say that the ice cube is a perfect cube, where each side is 1 cm long. Let's also say the ice cube is floating so that 0.8 cm is under water. How much does the ice cube weigh? To determine that, let's go over some calculations.

At Last Lets Try What Archimedes Tried to Say....Yes Its Time For Some Experimenting!!!!!!

An easy experiment for kids that doesn't need much materials to conduct the project. You will learn how to float an egg and why it floats!

HOW DOES IT WORK?

This experiment involves Archimedes' principle, an Ancient Greek scientist. A law of physics.

The egg is heavier than soft water, that's why it sinks in it. However, salt increases the density of the water which makes the buoyancy stronger, and makes the egg lighter. That is why it floats.

In the Middle-East, the Dead Sea has so much salt, that it is dense enough to make people foat without any effort!

NECESSARY MATERIALS

Two eggs

Two glasses of water

Coarse salt

A spoon

HOW TO MAKE THIS EXPERIMENT?

Plunge one egg into one of the glasses of water. You'll notice that it sink.

Pour salt into the other glass and stir it until it dissolves.

Plunge the other egg in the glass of salty water. It float.