physics test #4
Glass in a florist's greenhouse acts as a one-way valve in that it
allows high-frequency waves in and blocks low frequency waves exiting
A liter of cold water will warm faster in sunlight in a
black pot
A quantity of water has more entry when it is
boiling
In terms of transferring heat, red-hot wooden coals
conduct poorly
When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is
copper expands more than iron
When a volume of air is compressed, air temperature
decreases
The first law of thermodynamics is a restatement of the conservation of
energy
When most substances are heated, molecules inside move faster and take up more space, resulting in thermal
expansion
Compared with sea level cooking, in cooking eggs by boiling in mountain regions you should boil the eggs
for a longer time
Harry places a new air conditioner in the middle of his hot room, which when operating
further warms the room
A good absorber of radiation is a
good emitter of radiation
When you rapidly stir raw eggs with an eggbeater, the temperature of the eggs
increases
When an iron ring is heated, the hole becomes
larger
Place a 1-kilogram block of iron at 40◦C into 1 kilogram of water at 20◦C and the final temperature of the two after the thermal equilibrium is established becomes
less than 30◦C
The fact that desert sand is very hot in the day and very cold at night is evidence that the specific heat capacity of sand is relatively
low
Pour two liters of water at 40◦C into one liter of water at 20◦C and the final temperature of the two becomes
more than 30◦C.
To melt 50 grams of 0-degree-Celsius ice requires
none of the above
To turn 50 grams of boiling water to steam requires
none of the above
The form of heat transfer that doesn't depend on a medium is
radiation
The planet Earth loses heat primarily by
radiation
Water in a car radiator sometimes boils explosively when the radiator cap is removed, which is due to sudden
reduced pressure
The temperature of outer space is
about 2.7 kelvin
The lowest temperature possible in nature is
-273 degrees C
The lower the temperature of an object, the
-lower the frequency of radiation it emits -longer the wavelengths it radiates
To increase the temperature of 50 grams of water by 2 Celsius degrees requires
100 calories
The air pressure in a container of air at 27 C will double when heated to
327 degrees C
The change in internal energy of adding 100 joules to a system that does 60 joules of work is
40 J
The ideal efficiency for a heat engine operating between the temperatures of 227 C and 27 C is
40%
The calories needed to change 10 grams of ice at 0 C to steam at 100 C is
7200
If there were no greenhouse effect, Earth's average temperature would likely be
a frigid -18 C
Which of these is correct?
a piece of ice floats in water
When heat is added to boiling water, its temperature
remains unchanged
Blow on your hand with your mouth open. Then do the same with your lips puckered and you'll find
the breath from puckered lips is cooler
The reason that evaporation is a cooling process is
the more energetic molecules escape the liquid
Tomatoes have a higher specific heat capacity than dough. This means that when you bite into a hot pizza
the tomato sauce feels hotter than the dough
A refrigerator
transfers internal energy from inside to outside
The kind of molecular motion that mostly relates to the temperature of a substance is
translational motion
The cooling effect inside a refrigerator is produced by
vaporizing the refrigeration liquid
During a very cold winter, water pipes sometimes burst due to
water expanding when freezing
As a block of ice at 0 C melts, the block absorbs energy
without a temperature change