Which of the following is an example of the second law of thermodynamics?
A)Conversion of the energy in sunlight into glucose
B)The use of gasoline to propel your car
C)ATP activation of a proton pump.
D)A light bulb heats up after use
E)A nuclear reactor lights up the city.

Question

Which of the following is an example of the second law of thermodynamics?  
A)Conversion of the energy in sunlight into glucose
B)The use of gasoline to propel your car 
C)ATP activation of a proton pump.
D)A light bulb heats up after use
E)A nuclear reactor lights up the city.

Quizplus · Accepted Answer

The second law of thermodynamics states that in any energy transformation, the amount of usable energy will decrease and the amount of unusable energy or entropy will increase. In the case of a light bulb, electrical energy is transformed into light energy and heat energy, with the latter being unusable energy that increases the entropy of the system.

Answer: B
 The use of gasoline to propel your car is also an example of the second law of thermodynamics. The energy stored in the gasoline is transformed into kinetic energy to move the car, but some of that energy is lost as heat due to friction and other factors, increasing the entropy of the system.

Choices A and C are examples of energy transformations, but they do not necessarily illustrate the second law of thermodynamics since there is no discussion of usable vs. unusable energy or entropy. Choice E is more related to nuclear physics than thermodynamics.

Which of the Following Is an Example of the Second