Question
A 4-ton air conditioner removes $5.06 \times 10^7 \textrm{ J}$ (48,000 British thermal units) from a cold environment in 1.00 h. (a) What energy input in joules is necessary to do this if the air conditioner has an energy efficiency rating (EER) of 12.0? (b) What is the cost of doing this if the work costs 10.0 cents per $3.60 \times 10^6 \textrm{ J}$ (one kilowatt-hour)? (c) Discuss whether this cost seems realistic. Note that the energy efficiency rating (EER) of an air conditioner or refrigerator is defined to be the number of British thermal units of heat transfer from a cold environment per hour divided by the watts of power input.
1. $1.44 \times 10^7 \textrm{ J}$
2. 40.0 cents
3. This is realistic since it costs \\$9.60/day
Solution Video