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frozonecom
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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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