AP Environmental Science : Energy Conservation

Study concepts, example questions & explanations for AP Environmental Science

varsity tutors app store varsity tutors android store

Example Questions

Example Question #31 : Energy Production And Usage

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?

Possible Answers:

Correct answer:

Explanation:

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 #2 : Efficiency

What are net-zero-energy buildings? 

Possible Answers:

Buildings that yield as much or more energy than they need. 

Building that as insulated in such a way that they do not require a heating source. They are heated through light bulbs, humans, etc. 

Building that produce energy. 

Buildings whose windows are superinsulated. 

Building installed with solar panels. 

Correct answer:

Buildings that yield as much or more energy than they need. 

Explanation:

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 #1 : Cafe Standards

What does "CAFE" stand for when referring to the CAFE Standard?

Possible Answers:

Commercial Automotive Fuel Economy

Corporate Average Fuel Economy

Commercial Average Fuel Expenditures

Corporate Adjusted Fuel Economy

Commercially Applicable Fuel Expenditures

Correct answer:

Corporate Average Fuel Economy

Explanation:

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 #1 : Cafe Standards

How exactly does CAFE improve the average fuel economy of vehicles?

Possible Answers:

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 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 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 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.

Correct answer:

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.

Explanation:

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  miles per gallon in fuel economy. If a car company produces three cars, rated at 35, 30 and 20 mpg, average fuel economy would be determined as:

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 #2 : 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?

Possible Answers:

Companies that manufacture fuel-inefficient SUVs also manufacture fuel-efficient subcompact cars, resulting in an average fleet fuel economy that meets CAFE standards. 

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.

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.

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. 

Correct answer:

SUVs are often classified as a "light truck" and are exempt from the fuel economy standards put in place for passenger vehicles. 

Explanation:

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 #2 : 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?

Possible Answers:

Correct answer:

Explanation:

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 and they have sold passenger cars in U.S. markets, we can calculate the fine as such:

Therefore, the total penalties for Company A totals for the entire fleet.

Example Question #3 : 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 __________.

Possible Answers:

semi-trailer trucks

SUVs

cars

diesel trucks

Correct answer:

semi-trailer trucks

Explanation:

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.

Possible Answers:

30

25

40

27

Correct answer:

30

Explanation:

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.

Learning Tools by Varsity Tutors