ATMS 120: SP2014

Snodgrass

Name: ___________________________________Weekly Challenge Problem #8: Lightning Power

Due: Tuesday April 15, 2014Since man discovered that lightning was essentially a very powerful electric spark, we have been trying to develop ways to harness this power to provide electricity to our homes and cities.

For a typical lightning strike, the bolt is 5 km long, 2-3 cm wide, has a current between 15,000 and 30,000 amperes and can contain as much as 10 billion Joules of energy.

Part #1: How long (in days) would this amount of energy be able to supply power to Lincoln Hall? (You must show your work.)

Assumptions:

Assume all of the energy can be stored and used.

1 kilowatt-hour = 3.6 million Joules

Electricity consumed by each square foot each year = 14 kW-hours (kilowatt-hours)

Square Footage of Lincoln Hall = 107,477 ft2

There are 365 days in a year, 24 hours in a day.

Part #2: In reality, 1% of the energy in a lightning strike is electrical and the rest is heat. Repeat the same calculation you did in Part #1 assuming only 1% of the energy can be used to power the building. For how long can the lightning strike power Lincoln Hall? (provide your answer in hours)? (You must show your work.)

A popular movie in the mid-80s, Back to the Future claimed that time travel was possible through the combination of a Delorean, 88 mph, flux capacitor and a 1.21 jiggawatts of power. In the movie, Michael J. Fox, needs to get back to the future from 1955 and Doc Brown, played by Christopher Lloyd, calculates thats a lighting bolt could supply the necessary energy.

Part #3. Given the information below, calculate how many watts of power (1 watt = 1 J/s) are in a typical strike. Convert your answer to gigawatts (109 watts) and compare it to what the Delorean needs. (You must show your work.) Needed info:

Energy from a typical strike: 10 billion J (assume all of the energy goes into the flux capacitor)

Time for the return stroke of the lightning to travel between the cloud and the ground = 70 (s

((s = micro seconds = millionths of a second = 110-6 sec)

You can show all of your work on the back of this page. Just make it clear!