Fun With Electric Bills!

1) What is the unit of energy used on this electric bill? Please convert this awkward unit of energy to Joules, and then to calories. (One calorie equals 4.19 Joules.)

2) How many Joules of electricity did I use in the 30 days between November 14 and December 14?

3) Energy units are notoriously abstract, so let’s convert them into something more easily understood. If the electrical energy I used were instead converted to the kinetic energy of a moving car, how fast would the car be moving? Assume a mid-sized car with a mass of 1400 kg.

4) The combined weight of a class of physics students is roughly 17,000 N. If my total electrical energy consumption were instead used to toss students into the air, how far above the ground would the class be thrown? In other words, convert the electrical energy into gravitational potential energy.

5) According to the Burger King website, one Burger King Whopper® (with cheese) contains 710,000 calories of chemical potential energy. How many Whoppers® (with cheese) worth of energy did we use during the month?

6) Find the number of Joules I used per second. This is the average power consumption, in Watts.

7) What was the power consumption in horsepower?

8) My power consumption was the equivalent of how many 75 W light bulbs, lit constantly?

9) According to U.S. government surveys, the average American male consumes 2700 kilocalories every 24 hours. What is that average man’s power consumption in Watts? In horsepower?

10) Consider your answer to Question 9. The power consumption on my electric bill is equivalent to how many people?

11) Think carefully. What are the biggest sources of electrical energy consumption in your home?