Physics 140: Greenhouse Effect
Homework #1
due Wednesday, February 6, 2008
Problem 1 (4 points)
The gas tank in your car holds 13.2 gallons of gas. Show your work!
(a) If you get 30 miles per gallon, how far can you go on one tank of gas?
(b) If you were to improve your gas mileage by 10%, how far could you go?

Problem 2 (8 points)
Your house has an oil-fired heating system. Show your work!
(a) If you burn 5 gallons of heating oil per day in January, how much CO2 do you emit that month? Use 26 lbs of CO2 emitted per gallon of heating oil. How much carbon do you emit that month? Use 7.1 lbs of carbon emitted per gallon of heating oil.
(b) If there were a carbon tax of $60 per ton of CO2 , how much would the tax add to the price of a gallon of heating oil? (remember a ton is 2000 lbs)
(c) How much would the tax in (b) add to your heating oil bill for January?
(d) Search on the Internet for a recent news report (2007 or 2008) that gives the amount of a carbon tax proposed or
imposed by some national, regional or local government. How much is the tax per ton of CO2 or, if given that way, per ton of carbon (attach a printout of the page and be careful--a tax per ton of carbon just counts the weight of the carbon atoms--see part (b)). How much would the tax you found add to the price of a gallon of heating oil?

Problem 3 (8 points) Show your work!
(a) If you use heating oil as fuel at $3.80 per gallon, how much do you pay for 1 Btu?
(b) How many Btus does it take to bring 25 gallons of water from room temperature (72 F) to boiling point (212 F)? (1 gallon of water weighs 8.34 lbs.)
(c) If you use heating oil as the fuel, how much does it cost?
(d) If instead you use natural gas as the fuel at $13.50 per thousand cubic feet, how much does it cost to heat the water in (b)? Which is cheaper?


Energy content of various fuels
1 barrel (42 gallons) of crude oil = 5,800,000 Btu
1 gallon of gasoline = 124,000 Btu
1 gallon of heating oil = 139,000 Btu
1 gallon of diesel fuel = 139,000 Btu
1 barrel of residual fuel oil = 6,287,000 Btu
1 cubic foot of natural gas = 1,026 Btu
1 gallon of propane = 91,000 Btu
1 pound of coal = 10,000 Btu
<>1 kilowatthour of electricity = 3,412 Btu