AP Environmental Science : Energy Conservation
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Example Questions
Example Question #1 : Energy Conservation
Gasoline has an energy density of roughly 122.8 megajoules per gallon. A car company has produced a new economy car that has a fuel economy of 35 miles per gallon, and 0.877 MJ is exerted per mile to power the forward motion of the vehicle. What is the percent fuel efficiency of the car?
The fuel efficiency of the vehicle can be calculated as such:
This equation gives us the energy converted to forward motion per gallon of gas. We can use this value to determine the percent of total fuel energy that is devoted to forward motion:
From these calculations, we can determine that 25% of the energy from a gallon of gas is converted to actual forward motion of the vehicle, giving us a fuel efficiency value of 25%.
Example Question #1 : Efficiency
What are net-zero-energy buildings?
Building installed with solar panels.
Building that produce energy.
Buildings that yield as much or more energy than they need.
Buildings whose windows are superinsulated.
Building that as insulated in such a way that they do not require a heating source. They are heated through light bulbs, humans, etc.
Buildings that yield as much or more energy than they need.
All of the answers are part of energy conservation. But to be net zero the building has to produce energy and cannot be using any more than it produces.
Example Question #32 : Energy Production And Usage
What does "CAFE" stand for when referring to the CAFE Standard?
Corporate Average Fuel Economy
Commercial Average Fuel Expenditures
Commercially Applicable Fuel Expenditures
Commercial Automotive Fuel Economy
Corporate Adjusted Fuel Economy
Corporate Average Fuel Economy
CAFE is a standard enacted by U.S. Congress in 1975 with the objective to improve fuel economy for all vehicles produced for sale in the U.S. The acronym stands for Corporate Average Fuel Economy, because it applies to automotive corporations marketing cars in the U.S. and the objective was to improve average fuel economy.
Example Question #33 : Energy Production And Usage
How exactly does CAFE improve the average fuel economy of vehicles?
CAFE groups commercial vehicles and light trucks together and sets a minimum average fuel economy for the entire fleet, ensuring that companies manufacturing gas-guzzling commercial trucks also produce fuel-efficient and hybrid vehicles.
CAFE mandates a minimum average fuel economy for a manufacturer's fleet of vehicles to be sold in the U.S., and this standard increases over the years.
CAFE mandates a minimum average fuel economy for a manufacturer's fleet of vehicles to be sold in the U.S., and this standard has remained constant since 1975.
CAFE enforces federal emissions standards that increase annually. This standard applies to vehicles of all model years, and older vehicles often have to be modified to meet emissions standards and be legal to drive.
CAFE ensures that petroleum-producing companies are producing quality fuels that do not contain lead or sulphur levels above federal standards and contribute to air pollution.
CAFE mandates a minimum average fuel economy for a manufacturer's fleet of vehicles to be sold in the U.S., and this standard increases over the years.
CAFE is an ever-increasing average fuel economy standard that automobile manufacturers must satisfy in order to market their fleet of vehicles in the United States. This regulation is targeted toward new vehicles.
Example: Current CAFE standards mandate a manufacturer's fleet average 
Based upon their average fleet fuel economy, this car company could now sell their vehicles in the United States for the 2015 model year.
Example Question #1 : Cafe Standards
In recent years, many automotive companies have gotten away with marketing large SUVs with very poor fuel economy. How is this legally possible?
CAFE standards are not based upon the actual fuel economy of a fleet but rather the progress in fuel economy a manufacturer has made over the years. A fleet with poor fuel economy can be sold in the United States as long as the average fuel economy has improved from fleets of previous years.
SUVs are often classified as a "light truck" and are exempt from the fuel economy standards put in place for passenger vehicles.
Companies that manufacture fuel-inefficient SUVs also manufacture fuel-efficient subcompact cars, resulting in an average fleet fuel economy that meets CAFE standards.
Many of these large, fuel-inefficient SUVs were marketed and sold in the United States before CAFE standards were implemented and have thus been "grandfathered" in.
The vast majority of these fuel-inefficient SUVs are equipped with "flex-fuel" technology, which makes them eligible for an exemption from CAFE standards, implemented to encourage consumer purchase of American-produced corn ethanol.
SUVs are often classified as a "light truck" and are exempt from the fuel economy standards put in place for passenger vehicles.
The fuel economy standards established by CAFE are more strict and demand more fuel efficiency for passenger cars than for light trucks. Passenger cars are defined as having a Gross Vehicle Weight Rating (GVWR) of less than 8500 lbs, while a light truck is a vehicle with a GVWR greater than 8500 lbs. The light truck classification was initially for utility and commercial vehicles, but since many SUVs exceed the GVWR rating for a passenger car, they are regulated separately from the fleet of passenger cars and are not subject to stringent fuel economy standards.
Example Question #4 : Cafe Standards
Car Company A is in deep trouble with the U.S. Department of Transportation (DOT). It has been discovered that Company A's 2015 all-passenger car fleet has a mean fuel economy that falls short of the federal fuel economy requirements. Current fuel economy standards for passenger cars must average to 30.2mpg (miles per gallon) and the current penalty for non compliance is $5.50 for every 0.1mpg under regulations and multiplied by the number of cars in that years' fleet. If Company A's fleet has an average fuel economy of 29.8mpg with a total of 270,000 produced for U.S. markets, what will be the DOT fine imposed on the company?
First we want to determine the difference in minimum fuel economy standards and the actual fuel economy of Company A's fleet:
Given that Company A's fleet is out of compliance by 
Therefore, the total penalties for Company A totals 
Example Question #1 : Cafe Standards
Corporate average fuel economy (CAFE) standards are regulations in the United States set in place to improve the fuel economy of all the following vehicles except __________.
semi-trailer trucks
diesel trucks
SUVs
cars
semi-trailer trucks
Light trucks, such as diesel trucks and SUVs, are covered by CAFE standards, as well as cars. Semis, however, are not regulated by this legislature.
Example Question #2 : Cafe Standards
According to corporate average fuel economy (CAFE) standards, as of 2011, the standard fuel economy is more than __________ miles per gallon of gasoline.
25
27
40
30
30
We aren't quite to 40 miles per gallon yet, but 2011 was the first year that CAFE regulations set the standard for over 30 miles per gallon. The standard from 1990 up to 2011 was just over 27 miles per gallon, still a vast improvement from 1978's 18 miles per gallon.
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