Laws of Thermodynamics - AP Environmental Science

Card 0 of 2

Question

Most automobiles today have an energy efficiency of roughly 25% to 30%, meaning only a fraction of the potential energy from the gas you pump into your car will be converted into the kinetic energy of the car actually moving. Which of the following statements is true and best explains this phenomenon?

Answer

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.

Compare your answer with the correct one above

Question

Which Law of Thermodynamics explains how Earth is an open system?

Answer

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.

Compare your answer with the correct one above

Tap the card to reveal the answer