Thermodynamics
Cool a sample of air zero on the Celcius scale to near zero on the absolute scale and the air loses?
Pressure and volume
Entropy is closely related to the?
Second law of the thermodynamics
Two identical blocks or iron, one at 10 degrees c and the other 20 degrees c, are put in contact. Suppose the cooler block cools to 5 degrees c and the warmer block warms 25 degrees c. This would violet the?
Second law of thermodynamics
The ideal efficiency for a heat engine operating between temperatures of 2700 K and 300 K is?
89% Ideal efficiency=2700-300/2700 x 100
The lowest possible temperature in nature is?
-273 degrees C (absolute zero)
The temperature of an absolute is raised by 10 degrees Celcius. This is equivalent to what increase in its absolute temperature?
10 K Degrees on Celcius scale are the same size as those on the Kelvin scale.
At what temperature would the molecules of a gas have twice the average kinetic energy they have at a 20 degrees Celcius room temperature?
20 degrees Celcius x 2= 40 degrees Celcius +273= 313 Twice the K.E. means twice the temp.
A volume of air has a temperature of 0 degrees Celcius. An equal volume of air that is twice as hot has a temperature of about?
273 degrees C
One hundred joules of heat is added to a system that performs 60 joules of works. The internal energy change of the system is?
40 J Ideal efficiency=Thot-Tcold= 100-60
The first law of thermodynamics is a restatement of the?
Conservation of energy
If a blob 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
An absolute temperature of 200 K is the same as what Celcius temperature?
Degrees Celcius= K-273 200-273=-73 -73 degrees Celcius
An absolute temperature of 473 K is the same as what Celcius temperature?
Degrees Celcius= K-273 473-273=200 200 degrees Celcius
In buildings that are electrically heated, turning the lights on?
Doesn't waste energy
Adiabatic process occur in the?
Earth's mantle, oceans, atmosphere
The greater the difference in temperature between the input reservoir and output reservoir for a heat engine, the?
Greater the efficiency
Air high in the atmosphere that plunges downward tends to cool.
False
If all the friction could be eliminated in a heat engine, it's efficiency would be 100%.
False
If the internal energy of a volume of air at 100 degrees Celsius is doubled, it's temperature will then be 20 degrees Celcius.
False
It is possible to wholly convert a given amount of heat energy into mechanical energy.
False
Pull a closed plastic bad of dry air quickly down from a high elevation and the bag of air is?
Hotter
When a volume of air compresses 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
Entropy measures?
Messiness
Ceramic automobile engines that operate at higher temperatures will be?
More efficient
Systems that are left alone tend to move toward a state of?
More entropy
When mechanical work is done on a system, there can be a increase in its?
Temperature and internal energy
Efficiency in a heat engine is increased when there is a greater difference in input and output temperature.
True
It is possible to totally convert a given amount of mechanical energy into heat.
True
Systems left alone tend to move to a state of greater Entropy.
True
When work is done by system on something else the temperature of the system decreases .
True
Whenever heat is added to a system, it transformes to an equal amount of some other form of energy.
True
Running a refrigerator with its door open in a hot room makes the room?
Warmer
