Chapter 18 Science Review
Entropy is closely related to the
2nd law of thermodynamics
A quantity of water has more energy when it is
Boiling
When mechanical work is done on a system, there can be an increase in
Both temperature and internal energy
The first law of thermodynamics is a restatement of the
Conservation of energy
Blow on your hand with your open mouth and you feel the warmth of your breath. Pucker your lips so your breath expands as you blow and your breath is
Cooler
More efficient gasoline engines can be built if
Materials are developed that can withstand higher temperatures
During an adiabatic compression of an ideal gas
No heat s supplied to or removed from the gas
A temperature inversion occurs when the upper layers of air are
Warmer than the lower regions of air
The greater the difference in temperature between the input reservoir and the output reservoir for a heat engine, the
Greater the efficiency
To wholly convert a given amount of heat energy into mechanical energy is
Impossible regardless of the technique used.
As a system becomes more disordered, entropy
Increases
The lowest temperature possible in nature is
-273 degrees C
Two identical blocks of iron, on 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
2nd law of thermodynamics
One hundred joules of heat is added to a system that performs 60 joules of work. The internal energy change of the system is
40J
A heat engine would have 100% efficiency if it's input reservoir were
Any finite temperature if the exhaust sink were at absolute zero
Suppose you rapidly stir some raw eggs with an eggbeater. The temperature of the eggs will
Increase
As a blob of air at a high elevation sinks to a lower elevation with no heat input or output, it's temperature
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
Suppose you put a closed sealed can of air on a hot stove burner. The contained air will undergo an increase in
Internal energy, temperature and pressure
Systems that are left alone, tend to move toward a state of
More entropy