Energy Production and Usage - AP Environmental Science

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.

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.

The second law of thermodynamics states that when energy is converted from one form to another, some energy is lost and efficiency decreases. The energy from gasoline igniting is lost to friction from the engine and converting energy in the form of a combustion to the form of wheels rotating forward. Efficiency of energy use is lost in this conversion process.

The Second Law of thermodynamics states that the entropy on Earth can only increase unless there is an external source of energy. This external source is the Sun, which makes Earth an open system. Energy is able to flow both into an out of the Earth's energy system and explains phenomena such as evolution and global warming.

Electrical energy is form of energy that results from the motion of electrons.

Nuclear energy has the potential to last a long time; however, the quantity is finite and limited—similar to oil and gas. Solar energy, wind energy, and geothermal energy—from heat within the Earth—are produced by energy sources that do not deplete over time and can be constantly renewed.

Photosynthesis is the chemical process of utilizing the sun's radiant energy to produce glucose. Glucose is a carbohydrate monomer that is used for energy storage. Heat is not the type of energy utilized from the sun and the conversion of chemical energy into other forms is the reverse process of Photosynthesis.

The correct response is **potential energy.**This is stored energy at rest. It's energy waiting to be used. However, if the car was moving they would would call it kinetic energy - energy in motion. Since in the questions the car hadn't been started yet, kinetic energy is the incorrect response. Radiant energy is from the sunlight, thus that answer is incorrect. Metabolic energy is related to digestion so that response is incorrect.

The correct response is natural gas. This is an example of a fossil fuel - like coal and oil. Fossil fuels are considered non-renewable resources because once they are used up, they are gone forever. All of the other answer choices are considered renewable resources because they can be used multiple times without being depleted. For example, if an individual adds solar panels to their home, then they will receive energy day after day - sunlight is not completely used up by the solar panels.

A kilowatt-hour is a unit of energy equal to one thousand watt-hours. A watt-hour is the amount of energy used to power a hypothetical device for one hour that requires one watt of energy to function. Thus, a kilowatt-hour is used to measure energy consumption.

While coal was the predominant source of energy during the Industrial Revolution, advancements in petroleum extraction and refining resulted in petroleum and natural gas becoming the dominant industrial fuel source in the 1950s. This pattern has existed to this day.

The Energy Star certification is a standard of energy efficiency for consumer electronics and appliances that is higher than what is required by federal standards. The program was a joint venture by the Environmental Protection Agency and Department of Energy and has since become an internationally-recognized standard.

The least efficient and most abundant form of coal is lignite; after this comes bituminous coal, then, lastly, anthracite. Anthracite is a very hard form of coal with an extremely high carbon content. Anthracite also burns the cleanest of any coal, but unfortunately it is the least abundant and hardest to reach form of coal. Charcoal is not coal at all, but rather compressed and burned wood, consisting mainly of carbon and any remaining ash.

Electric cars with a gas engine are classified as Hybrids, not All-Electric Vehicles. The other answers address the environmental impact of manufacturing and parts, and while these impacts are substantial, their ongoing impact is miniscule when compared to the footprint from regular driving. The majority electricity in America is generated by the burning of fossil fuels, which means driving an electric car regularly still has a carbon footprint and a significant one at that.

The tragedy of commons is a term used today to describe a situation wherein individuals acting independently and rationally according to their own self-interest behave contrary to the best interests of the greater population by depleting a common resource. In opposition, the examples of ranchers managing common ground and collective farming of grapes are examples of individuals working together in a common interest. Additionally, allocating nuclear waste to one area is rather an example of sacrificing a small area for the greater population, and using national forests for wood production and harvesting is simply disobeying the everyone's interests by depleting resources and breaking the law. However, the depletion of fishing stocks is a perfect example of the tragedy of the commons: It is the ravaging of a greater population's shared natural resource in favor of individual and commercial interest.

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.

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.

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.

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%.