Homework: Energy use and the Statue of Liberty

Energy is measured in many ways and with many different units. Sometimes we use kilowatt-hours in which the number of kilowatts (which is a measure of power or energy-per-unit-time) is multiplied by hours (a measure of time). Sometimes energy is defined as "force times distance" using foot-pounds.

2,000 foot-pounds is the energy it takes to lift 2,000 pounds up by 1 foot. It's also the energy it takes to lift 1 pound up 2,000 feet, and so forth.

120 kilowatt-hours similarly is both (a) the amount of energy used is you use 12 kilowatts for 10 hours or (b) if you use 6 kilowatt for 5 hours.

Excluding the many thousands of tons in the concrete base, the Statue of Liberty weighs about 450,000 pounds; together with its heavy concrete foundation, it weights 54 million pounds. How much energy does one (average) US household use in one year, converted into how many feet the Statue of Liberty could be lifted with such energy?

Assume the average U.S. household uses about 12,000 kWh/yr. A kilowatt-hour (kWh) is the amount of energy used when one kilowatt of power is run for a full hour.

We cannot yet use Google Calculator since it cannot currently understand "12345 kilowatt-hours in foot-pounds"

However, use the fact that 1 watt-hour equals 3600 Joules (a Joule is a unit of energy; it is equal to one "watt-second") to convert the average US Household energy figure into joules. Notice that there are a thousand "watt-hours" in one kilowatt-hour as well as the 3600 to 1 factor; you'll need to use both.

Once you have a (large!) number representing the number of joules of energy the average US household uses per year, use Google Calculator to convert that into foot-pounds (you will type the analog of "123456789 joules in foot-pounds" into google, where you use the correct figure instead of "123456789").

How many feet in the air would the full Status of Liberty plus Base (a total of 54 million pounds) be lifted by the amount of energy one US household uses in a year?

How many feet in the air would the full Status of Liberty alone (which weighs 0.45 million pounds) be lifted by the amount of energy one US household uses in a year?