What is the buoyant force exerted on the balloon in air

AI Thread Summary
The buoyant force on a helium-filled balloon in air is calculated using Archimedes' Principle, which states that the buoyant force equals the weight of the displaced fluid. The correct formula for the buoyant force is Fb = (density of air) x (volume of balloon) x (acceleration due to gravity). The initial calculation mistakenly used kilometers instead of kilograms for density, leading to confusion about units. The correct density for air is 1.3 kg/m^3, and the calculation should yield a buoyant force of 0.115 N. Accurate unit usage is crucial for proper application of the principle.
Eng67
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Is this a correct interpretation of Archimedes Principle for this application?

A balloon is filled with helium (density = .02 kg/m^3) and has a volume of .009 m^3. What is the buoyant force exerted on the balloon in air
(density = 1.3 km/m^3)?

Fb = (1.3 km/m^3)x (.009 m^3) x (9.80 m)

= .115 N

Thanks
 
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Yes. Archimedes' Principle says that the buoyant force on an object equals the weight of the displaced fluid.
 
Nitpick! Mass is measured in kg, not km. The latter is a measure of distance.
 
Ya.. Eng67, u'r units are all wrong
Unit for density: kg/m^3
Unit for gravity: m/s^2
 
Thanks for the help Guys. I just typed in Km instead of Kg.
 

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