Physics Chapter 24
Running a refrigerator with its door open in a hot room makes the room...
Warmer
If a volume of air is swept upward with no heat input or output, its temperature will do what?
decrease
When work is done by a system and no heat is added to it, the temperature of the system...
decreases
The greater the difference in temp between the input reservoir and output reservoir for a heat engine, the..
greater the efficiency
In buildings that are electrically heated, turning the lights on... doesn't waste energy wastes energy does neither of the above
does NOT waste energy
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 does what?
increases
True or False: It is possible to wholly convert a given amount of heat energy into mechanical energy.
False
True or False: If all the friction could be eliminated in a heat engine, its efficiency would be 100%.
False.
What does entropy measure?
Messiness
When mechanical work is done on a system, there can be an increase in its... temperature internal energy both of the above none of the above
both; temperature AND internal energy
Systems that are left alone tend to move toward a state of...
more entropy
Adiabatic processes occur in...
Earth's mantle the oceans the atmosphere
True or False: Air high in the atmosphere that plunges downward tends to cool.
False
Entropy is closely related to what law of thermodynamics?
Second law of thermodynamics
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 0 + 273= (273 K) x 2 - 273 = 273 degrees C
Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses... Volume Pressure Both of the above Neither
Both; volume AND pressure
True or False: If the internal energy of a volume of air at 10 degrees C is doubled, its temperature will then be 20 degrees C.
False
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 and the warmer block warms to 25 degrees C. this would violate the...
Second Law of thermodynamics
True or False: Efficiency in a heat engine is increased where there is a greater difference in input and output temperatures.
True
True or False: It is possible to wholly convert a given amount of mechanical energy into heat.
True
True or False: Systems left alone tend to move to a state of greater entropy.
True
True or False: When work is done by a system on something else, the temperature of the system decreases.
True
True or False: Whenever heat is added to a system, it transforms to a equal amount of some other form of energy.
True
Pull a closed plastic bag of dry air quickly down from a high elevation and the bag of air will become...
hotter
Suppose the temperature of the input reservoir in a heat engine does not change. As the sink temperature is lowered, the efficiency of the engine...
increases
