- #1
clutchstrike
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Homework Statement
An empty rubber balloon has a mass of .0120 kg. The balloon is filled with helium at a density of .181 kg/m^3. At this density the balloon is spherical with a radius of .500m. If the filled balloon is fastened to a vertical line, what is the tension in the line?
Homework Equations
Equations that I found:
volume of a sphere = 4/3(pi)(r^3)
density = mass/volume
Buoyant force = weight
The Attempt at a Solution
I attempted to set up a free body diagram, with two forces. One is the tension going up, and the other is weight going down. That would mean T = mg. since density = mass/volume, .181 kg/m^3 = mass / (4/3)(pi)(.5)^3. That gets a mass of .095g.
.095g(9.8 m/s^2) = .929 N. The correct answer is 5.57 N. So, I got it wrong.