Thread: chem/math

Fat tissue is 85 % fat and 15 % water. The complete breakdown of the fat itself converts it to CO2 and H2O, which releases 9.0 kcal per gram of the fat in the tissue.
a) How many kilocalories are released by the loss of 1.0 lbs of fat tissue in a weight reduction program? ( 2.2 lbs = 1.0 kg)
b) A person running 8.0 miles hr^-1 expends about 5.0 x 10^2 kcal hr^-1 of extra energy. How far does a person have to run to burn off 1.0 lbs of fat tissue by this method alone?

Originally Posted by william

Fat tissue is 85 % fat and 15 % water. The complete breakdown of the fat itself converts it to CO2 and H2O, which releases 9.0 kcal per gram of the fat in the tissue.

a) How many kilocalories are released by the loss of 1.0 lbs of fat tissue in a weight reduction program? ( 2.2 lbs = 1.0 kg)

Energy Released = 9 kcal/g = 9 000 kcal/kg = (9000/2.2) / (1/2.2kg) = 4090.9 kcal/lb(1 d.p)

b) A person running 8.0 miles hr^-1 expends about 5.0 x 10^2 kcal hr^-1 of extra energy. How far does a person have to run to burn off 1.0 lbs of fat tissue by this method alone?

Hours required = Energy consumed / Rate of energy consumption

= 4090.9 kcal (because we're burning one lb)/ 5 x 10² kcal/hr

= 8.18 h (2 d.p.)

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