Thermodynamics!

If a volume of air is swept upward with no heat input or output, its temperature

decreases

When work is done by a system and no heat is added to it, the temperature of the system

decreases

Air high in the atmosphere that plunges downward tends to be cool

false

If all the friction could be eliminated in a heat engine, its efficiency would be 100%.

false

In buildings that are electrically heated, turning the lights on

doesn't waste energy

The first law of thermodynamics is a restatement of the

conservation of energy

Entropy measures

messiness

Systems that are left alone, tend to move toward a state of

more entropy

what does it mean to say that energy becomes less organized when it transforms form one form to another

It means that it is the only process that can result in an increase in entropy. To have greater entropy there must be lower energy.

How does the second law of thermodynamics relate to the direction of heat flow

It states that heat flows from a hot source to a cold source

The greater the difference in temperature between the input reservoir and output reservoir for a heat engine, the

greater the efficiency

An absolute temperature of 110K is the same as what celsius temperature

-163C

The lowest possible temperature in nature is

-273 degrees Celsius

An absolute temperature of 47K is the same as what celsius temperature

200C

80 joules of heat is added to a system that performs 55 Joules of work. The internal energy change of the system is

25J ( 55=80-Qc) Qh-Qc=work

A volume of air has a temperature of 0 degrees celsius. An equal volume of air that is twice as hot has a temperature of about

273 degrees C

At what temperature would molecules of gas have twice the average kinetic energy they have at 26C room temperature

325C

Calculate the ideal efficiency of a power plant that runs between temperatures 400K and 150K

63%

The temperature of an object is raised by 70C This is equivalent to what increase in its absolute temperature

70

There is a type of power plant known as OTEC that operates on the temperature of difference between warm surface waters and cool deep waters. what is the Carnot efficiency of such a power plant if the surface water is 25C and the deep water is 4c

84%

The ideal efficiency for a heat engine operating between temperatures of 2700 K and 300 K is

85% ( 2050-310=1740/2050=84.5 X 100)

Make up three examples to illustrate that natural systems tend to proceed toward greater entropy

An abandon house, burning campfire, cream spreading in coffee

Adiabatic process occur in

Earths mantel, the oceans, the atmosphere ( all of the above)

Ceramic automobile engines that operate at higher temperatures will be

More efficient

You have a jar full of marbles. When you tip the jar over, all of the marbles roll away. You would not expect the marbles to spontaneously order themselves back into the jar because

Process in which disorderly states tend toward orderly states are improbable and simply not observed.

When mechanical work is done on a system, there can be an increase in its

Temperature and internal energy ( both of the above)

distinguish between the first and second laws of thermodynamics in terms of whether or not exceptions occur

The first law has no exceptions, simply states that you can't lose or gain any energy than what you had, the 2nd law says actually the only way to have 100% efficiency is to be at 0k

It is possible to totally convert a given amount of mechanical energy into heat

True

If the internal energy of a volume of air at 10C is doubled, its temperature will then be 20C

false

It is impossible to wholly convert a given amount of heat energy into mechanical energy

false

Pull a closed plastic bag of dry air quickly down from a high elevation and the bag of air will become

hotter

When a volume of air is compressed and no heat enters or leaves, the air temperature will

increase

As a system becomes more disordered, entropy

increases

Suppose the temperature of the input reservoir in a heat engine doesn't change. As the sink temperature is lowered, the efficiency of the engine

increases

Give two reasons why a tire pump becomes hotter when used to pump a tire

its energy is increased and there is external work done on it.

Entropy is closely related to the

second law of thermodynamics

Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This would violate the

second law of thermodynamics

Efficiency in a heat engine is increased when there is a greater difference in input and output temperatures

true

Systems left alone tend to move to a state of greater entropy

true

When work is done by a system on something else, the temperature of the system decreases

true

Whenever heat is added to a system, it transforms to an equal amount of some other form of energy.

true

Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses

volume and pressure ( both A and B)

Running a refrigerator with its door open in a hot room makes the room

warmer