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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: Studyinghard on April 12, 2011, 05:28:07 pm

Title: Metabolic Rate
Post by: Studyinghard on April 12, 2011, 05:28:07 pm

A person is breathing air at sea level. As a result of metabolism the air expired has 13% oxygen (compared to 21% for air inspired). If the person breathes a total volume of 3.3 litre of air per minute, what is the person's metabolic rate, in watt?

Title: Re: Metabolic Rate
Post by: Studyinghard on April 12, 2011, 05:56:24 pm

1l of oxygen = 20.2 KJ if that helps.

I got 18.5 w but dont know if thats right

Title: Re: Metabolic Rate
Post by: schnappy on April 12, 2011, 06:32:30 pm

Quote from: Studyinghard on April 12, 2011, 05:56:24 pm

1l of oxygen = 20.2 KJ if that helps.

Yeah, makes it possible :P

3.3l of O_2 ---> 66.66kJ
P=(66.66*1000)J/(60)s
P=1111 W

Not sure what the go is with this 21% air inspired though? I'm assuming the metabolic rate is the energy/time of oxygen intake, where the amount of oxygen is 13% of the 3.3l.