Question

It takes 41.7 BTUs to heat a 5 gallon jug of water. What is the density of a gallon of water. Round your answer to the nearest hundredth

Answer 1

Answer: The density is 0.002 lb/cm^3

Explanation:

1 BTU is neded to increment the temperature of 1 Lb of water by 1° F

Then if we need 41.7 BTU to increment 1°F of 5 gallons of water, this means that in the 5 gallons we have a mass of 41.7 lbs of water.

And as you know, density = mass/volume

now, 1 gallon = 3.78 liters = 3780 cm^3

then 5 gallons = 5*3780 cm^3 = 18900 cm^3

The density is D = 41.7Lb/18900 cm^3 = 0.002 lb/cm^3