« previous next »

Author Question: What is the essential reason that all perpetual motion machines fail? a. Perpetual motion machines ... (Read 85 times)

ashley

  • Hero Member
  • *****
  • Posts: 584
on: Jul 28, 2018
What is the essential reason that all perpetual motion machines fail?
 a. Perpetual motion machines must create energy in order to do useful work, and energy cannot be created.
  b. Perpetual motion machines must at least preserve all the energy in a system, and some is always lost.
  c. Perpetual motion machines run on gasoline, and gasoline is not a renewable resource.
  d. A perpetual motion machine necessarily removes heat from a single-temperature environment.
  e. Perpetual motion machines have to contend with friction, which destroys energy.

Question 2

A refrigerator uses mechanical work to transfer heat from a colder region to a hotter one, as shown in this schematic. Why is it not possible to remove heat from the cold region and transfer it to the hot region without the input of work by an external source?
 a. It would violate the first law of thermodynamics.
  b. It would violate the second law of thermodynamics.
  c. Both a. and b.
  d. It would be possible only if the machine did not lose some energy as heat because of friction.


Li Jun

  • Sr. Member
  • ****
  • Posts: 335
Reply #1 on: Jul 28, 2018
Answer to Question 1

b

Answer to Question 2

b


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Fatal fungal infections may be able to resist newer antifungal drugs. Globally, fungal infections are often fatal due to the lack of access to multiple antifungals, which may be required to be utilized in combination. Single antifungals may not be enough to stop a fungal infection from causing the death of a patient.

Did you know?

In ancient Rome, many of the richer people in the population had lead-induced gout. The reason for this is unclear. Lead poisoning has also been linked to madness.

Did you know?

A serious new warning has been established for pregnant women against taking ACE inhibitors during pregnancy. In the study, the risk of major birth defects in children whose mothers took ACE inhibitors during the first trimester was nearly three times higher than in children whose mothers didn't take ACE inhibitors. Physicians can prescribe alternative medications for pregnant women who have symptoms of high blood pressure.

Did you know?

Asthma cases in Americans are about 75% higher today than they were in 1980.

Did you know?

Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.

Effective communications skills are essential to the medical assistant’s career Effective communications skills are essential to the medical assistant’s career
Ten Foundational Essential Oils Ten Foundational Essential Oils
Apply effleurage with wave motion to posterior cervical region. Use fingertips to slide along ... Apply effleurage with wave motion to posterior cervical region. Use fingertips to slide along ...
Vegetable oils are good sources of essential fatty acids Vegetable oils are good sources of essential fatty acids
Physics 12 - Interpreting Motion Physics 12 - Interpreting Motion
Newton's Second Law of Motion: Use G.R.E.S.A. format Newton's Second Law of Motion: Use G.R.E.S.A. format
Video: Introduction to Sleep Apnea

For a complete list of videos, visit our video library