Question

Can someone explain Archimedes' Principle? My book keeps talking about buoyancy and I'm not understanding it.

Answer 1

@sleepyhead314 @thomaster

Answer 2

The part I'm really messed up on is this "The buoyant force exerted by a liquid is exactly equal to the weight of the liquid displaced." I'm unsure what displaced means.

Answer 3

it is like how mass of water displaced = mass of stuff placed into water

except this one results in being able to make an inference to the density of the object...
I think... I didn't do so well in my physics class tho

Answer 4

mmmm dis! https://upload.wikimedia.org/math/2/3/7/237bee86559c5c0d935068fd88c93d5d.png

Answer 5

ok. It makes a little bit more sense. I get that you put something in water and mass is lost. I just am really confused because I'm not sure what displaced means in that sense.

Answer 6

like if you had a graduated cylinder, it would be how much the water rises

Answer 7

ohh. So I put a brick in a bath tub or something and measure the amount of water I put in before I put the brick in. Then once I do put the brick in I measure how much is in there now and subtract? That would be the amount of mass lost?

Answer 8

more equations than that .-.

Answer 9

in a general sense would that be right?

Answer 10

the actions yes
but you wouldn't magically get the mass lost by subtracting

Answer 11

if you have a graduated cylinder half filled with water

you make note of the mass/volume of water/height in relation to the cylinder

you take note of the original mass of a marble
convert that mass into Newtons

you put the marble into the cylinder with the water

make note of the increase in height

calculate the volume of water that increased

convert that to Newtons

that would be the new Newtons of your marble

subtract Original Newtons by new Newtons of the marble to find the lost mass

Answer 12

Ok. My book is going over this for specific gravity. And in order to find specific gravity, you have this formula- \[S.G=\frac{ mass~of~object }{mass~of~water~displaced~by~the~object }\]
Right? If I know the mass of water displaced by the object, I can find Specific Gravity?

Answer 13

not the right formula?
http://study.com/cimages/multimages/16/specificgravityformula1.png

Answer 14

ohhh nvm I see what you're saying

but it still should be (weight of object) / (weight of displaced fluid)

note: weight and mass are different things

Answer 15

okie. I think I get this now. Thanks so much for helping me!

Answer 16

glad I could help ^_^