# What is the buoyant force exerted on the balloon in air

1. Jun 23, 2005

### Eng67

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

2. Jun 23, 2005

### Staff: Mentor

Yes. Archimedes' Principle says that the buoyant force on an object equals the weight of the displaced fluid.

3. Jun 23, 2005

### SGT

Nitpick! Mass is measured in kg, not km. The latter is a measure of distance.

4. Jun 23, 2005

### gunblaze

Ya.. Eng67, u'r units are all wrong
Unit for density: $$kg/m^3$$
Unit for gravity: $$m/s^2$$

5. Jun 24, 2005

### Eng67

Thanks for the help Guys. I just typed in Km instead of Kg.