AP Environmental Science : AP Environmental Sciences

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #371 : Ap Environmental Sciences

Which of the following is NOT a drawback of utilizing hydrogen as a fuel source?

Possible Answers:

Hydrogen is very challenging and dangerous to transport.

Hydrogen has a low energy density by volume.

The input of energy to produce hydrogen is often greater than the energy of the resulting hydrogen.

Existing infrastructure for manufacturing and transporting hydrogen is minimal to nonexistent.

Hydrogen has a low energy density by weight.

Correct answer:

Hydrogen has a low energy density by weight.

Explanation:

Hydrogen is very challenging to transport and it requires a large energy investment to produce it. While hydrogen has a low energy density by volume, it actually has a very high energy density by weight. This has to do with the fact that hydrogen, discussed in this context, is a gas.

Example Question #372 : Ap Environmental Sciences

Which of the following is NOT correct about geothermal energy?

Possible Answers:

While sustainable, geothermal plants do emit small quantities of carbon dioxide and some toxic gases, originally trapped in gas pockets deep below the surface.

Iceland has been able to utilize geothermal to meet over twenty-five percent of their energy demand, in large part because of the geothermal activity of the region.

Fuel consumption of geothermal plants is insignificant when compared to that of coal and natural gas plants.

Geothermal energy can be harnessed in any region of the world and contribute substantially to the power grid.

Geothermal has proven cost-effective in remote communities where importing fuel is challenging and expensive.

Correct answer:

Geothermal energy can be harnessed in any region of the world and contribute substantially to the power grid.

Explanation:

Geothermal activity has proven to be a cheap, low-cost and environmentally friendly energy source for communities located in areas with high geothermal activity, particularly where the earth's crust is rather thin (e.g. Iceland); however, this method of harvesting energy is not very economically feasible or possible in areas with little near-surface geothermal activity.

Example Question #373 : Ap Environmental Sciences

Which of the following most accurately defines "Synfuel"?

Possible Answers:

A liquid fuel processed from a non-petroleum material such as coal or waste plastics.

A derivative of waste plastics that results in a form of kerosene

Synthetic fuel, derived exclusively from non-organic sources as opposed to organic sources (e.g. biodiesel, ethanol, etc.)

Fuel synthesized in a laboratory as opposed to refined from crude oil

A counterfeit fuel produced by illegitimate companies that can prove harmful to industry when mixed with fuel reserves

Correct answer:

A liquid fuel processed from a non-petroleum material such as coal or waste plastics.

Explanation:

Synfuel is derived from waste plastic, coal, natural gas and other non-petroleum sources. It is a liquid fuel and the process of deriving synfuel can produce gasoline, diesel, and kerosene.

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?

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:

Building installed with solar panels. 

Buildings whose windows are superinsulated. 

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. 

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 #31 : Energy Production And Usage

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

Possible Answers:

Commercial Automotive Fuel Economy

Commercial Average Fuel Expenditures

Commercially Applicable Fuel Expenditures

Corporate Average Fuel Economy

Corporate Adjusted Fuel Economy

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 #2 : 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 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 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 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. 

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 #32 : Energy Production And Usage

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:

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.

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. 

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.

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.

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 #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?

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 #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 __________.

Possible Answers:

semi-trailer trucks

diesel trucks

SUVs

cars

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.

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