Archimedes' Principle

Purchase: http://hilaroad.com/video/
This video explains how to calculate the weight of a horse using Archimedes' Principle.
Includes a demonstration with digital scales and overflow apparatus.
The forces acting on hot air balloons, cargo and cruise ships is explained by this principle from the ancient Greeks.
Marine architects and engineers use this basic principle to design floating structures - ships, submarines and oil rigs.
Suitable as a learning resource for an introduction to buoyancy and Archimedes in physics and general science.

• Category

  Education

[heratioalundi]

what happens when you have two cubes of the same volume but different density that completely sink ? 

A brick of iron in that tub will displace the same amount of water as a brick of gold, even though their density is different, when both are at the bottom of the tub.

Seams to only work with floating object, or using floating object as a pressure pad.

How would you measure the density of a cube of gold while a cube of iron will sink just as well? By placing it on a piece of wood?

[ScienceOnline]

The buoyant force acting on an object completely submerged in water equals the weight of the displaced water. In this example the volume of the displaced water equals the volume of the brick.

Both the gold and iron bricks will experience the same buoyant force (assuming they are the same volume). The net force down (force of gravity - buoyant force) acting on the gold block will be greater because it is denser, therefore heavier, then the iron brick). .....

[ScienceOnline]

Placing the brick on floating wood displaces a weight of water equal to the weight of the brick.

[heratioalundi]

"The buoyant force acting on an object completely submerged in water equals the weight of the displaced water."

if i had both a solid iron brick and a hollow thin shell brick (with air inside) both of the same volume, would they experience the same buoyant force when completely submerged?

[ScienceOnline]

Yes, but you might have to push and hold the hollow one under water. This happens when the buoyant force exceeds the weight of the object.

[Maarten Vergucht]

You gave me the image of the clever grandpa or uncle I always wanted to have who fascinates his grandchildren, nephews and nieces about the basic laws of nature, the stars, etc... With a reliable knowledge where even their teachers in school can have a lesson from... And that impression is great!!

Your (grand)children, if you have them, are blessed with such a teacher in life.

[vissvienna]

It would've been great having these videos when I was in school back in the 80's!!

Another great video.

[Charles Regimbal]

i showed this to my science teacher. he loved it!

[Gabriel Esguerra]

in archimedes' time, the king ordered someone to make a crown from a brick of gold. then the crown is made and when they check it, the mass of a standard brick of gold is equal to the mass of the crown. but archimedes doubt that the crown is not made of pure gold. in the end, he placed both objects, the brick and the crown, in a container with the same amount of water. the crown displaces more water than the gold. i thought that the mass of an object is equal to the mass of water displaced.

[codewalters]

Excellent lessons !!!

[0x96C]

Cool! Thanks for this upload.

[UniversalVision]

Ah. So and the significance of the name Archimedes makes this ever so relevant.

But I gotta say this is though basic chemistry, its applications are useful when extended to nautical engineering. Also, I have to admit that I came across this video after watching "Meet the Medic", which have no relevance to science but in particular mad science! LOL! And video games.

[silenthorsewhisperer]

This can be used to show how full scale boat lifts (with water in them) work even if the lifting ram is just in the centre and the boat moves. Great physics - keep up the good work!

[silenthorsewhisperer]

Great video! As will all physics just doing the maths is not enough! It would be good if it explained why the water is displaced and the block sinks in to a certain depth! Some understanding of pressure and particle motion is required. I will give you all an example to demonstrate - if you hang a rectangular tank half full of water from its midpoint (over the centre of mass) and place a floating boat in the tank - even if it (gently) moves to the left or right the tank does not tip....

[ugotmeggedhardcore]

I'm in grade 8, and i have a test coming up about this. but it was too much info, but fun to learn! i totally get it, and now im ready! thanks!

[canadianslang]

good and well detailed video, this helped me with my project thanks!

[Jaivardhan Kapoor]

that horse is overweight....