A swimming pool heater has to be able to raise the temperature of the 60,000 gallons of water in the pool by 11.0 C°.How many kilowatt-hours of energy are required? (One gallon of water has a mass of approximately 3.8 kg and the specific heat of water is 4,186 J/kg⋅°C. )

Question

A swimming pool heater has to be able to raise the temperature of the 60,000 gallons of water in the pool by 11.0 C°.How many kilowatt-hours of energy are required? (One gallon of water has a mass of approximately 3.8 kg and the specific heat of water is 4,186 J/kg⋅°C. )
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Quizplus · Accepted Answer

First, we need to calculate the total heat energy required to raise the temperature of 60,000 gallons of water by 11.0 C°.

Mass of water in gallons = Volume of water in gallons x Density of water = 60,000 x 3.8 = 228,000 kg

Energy required = mass x specific heat x temperature change

= 228,000 x 4,186 x 11.0

= 10,526,568 J

Now, we need to convert Joules to kilowatt-hours (kWh):

1 J = 2.77778 x 10^-7 kWh

Therefore,

10,526,568 J = 10,526,568 x (2.77778 x 10^-7) kWh

= 2.92 kWh

Hence, the answer is B) 2,920 kWh.

A Swimming Pool Heater Has to Be Able to Raise