A person can change the volume of his body by taking air into his lungs. The amount of change can be determined by weighing the person underwater. Suppose that underwater a person weights 20.0 N with partially full lungs and 40.0 N with empty lungs. Find the change in body volume.
2006-12-18 10:17:52 · 2 answers · asked by candy 3 in Science & Mathematics ➔ Physics
The difference in the person's apparent weight underwater is equal to the difference in the weight of the displaced water while the air was still in the person's lungs.
If after the air is let out of the person's lungs, the apparent weight increases by 20.0 Newtons, then that is the same weight of the volume of water which was originally displaced.
To find the mass of the displaced water (gravitational acceleration = 9.81 m/s^2),
Weight = mass * gravity
20.0 Newtons = mass * 9.81 m/s^2
mass = 20.0 N / 9.81 m/s^2
mass = 2.04 kilograms
To find volume of the water (which will equal the change in volume of the person), use the density of water (which we will assume to the 1 g/mL = 1 kg/L).
Density = mass / volume
1 kg / L = 2.04 kg / volume
volume = 2.04 kg / 1 kg/L
volume = 2.04 Liters
Therefore, the volume of the person changes by 2.04 Liters after the air is released from their lungs.
2006-12-18 10:55:27 · answer #1 · answered by mrjeffy321 7 · 0⤊ 0⤋
Yes. That's what other people are FOR. I do things at home. At the office, I'm all about being served. And I say that with two syllables - ser. ved. More regal that way.
2016-05-23 05:24:30 · answer #2 · answered by Anonymous · 0⤊ 0⤋