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## Homework Statement

A piece of metal weighs 50.0 N in air, 36.0 N in water and 41.0 N in oil. Find the densities of the metal and the oil.

## Homework Equations

Density of Water is 1000 kg / m[itex]^{3}[/itex]

Density of Air is 0.00121 g / cm[itex]^{3}[/itex]

## The Attempt at a Solution

I really don't have any idea on how to solve the problem but I gave it a try :

Buoyant Force = Weight in Air - Apparent Weight on Fluid

so, Buoyant Force in Water = 50.0 N - 36 N

Buoyant Force in Water = 14 N

Converting the Weight of Displaced Water(Buoyant Force) to Mass gives :

14 N [itex]\div[/itex] 9.8 m/s[itex]^{2}[/itex]

Mass of Displaced Water = 1.43 kg

To get the volume of Water Displaced (Which is the same as the Volume of the Metal.... PLEASE CORRECT ME IF I'M WRONG BUT THIS IS WHAT I UNDERSTOOD FROM READING THE BOOK!!!) we do:

Volume of Water= Mass / Density

Volume = 1.43 kg [itex]\div[/itex] 1000 kg / m[itex]^{3}[/itex]

Volume of Water = 1.43 x 10[itex]^{-3}[/itex] m[itex]^{3}[/itex]

----- Which is also the Volume of the Metal....

To get the Density of Metal we need the Mass and Volume of the Metal. From this part, how do I get the density of Metal? How do I get the Mass of the Metal ?? How do I get the Density of the oil?

Buoyant Force in Oil = Weight in Air - Weight in Oil

Buoyant Force in Oil = 50.0 N - 41.0 N

Buoyant Force in Oil = 9 N

Converting it to Mass gives 0.92 kg.

Please help?

/frozonecom

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