|
Thermal convection applies mainly to _________. |
fluids |
|
Heat travels from the Sun to Earth by the process of _________. |
radiation |
|
The relation f ~ T tells us that high temperature sources emit electromagnetic waves of _________. |
high frequency |
|
How does the peak frequency of radiant energy relate to the absolute temperature of the radiating source? |
The peak frequency increases as temperature increases. |
|
Which will normally warm faster: a black pot of cold water or a silvered pot of cold water? Which will cool faster? |
black , black |
|
Solar power is the rate at which _________. |
solar energy is received from the Sun |
|
Which of the following most prevents the escape of terrestrial radiation? |
Water vapor |
|
Newton’s law of cooling applies to objects that undergo _________. |
cooling or warming |
|
Which will undergo the greater rate of cooling: a red-hot poker in a warm oven or a red-hot poker in a cold room (or do both cool at the same rate)? |
The poker in the cold room cools fastest. |
|
How much radiant energy from the Sun, on average, reaches each square meter at the top of Earth’s atmosphere each second? What is the average solar power, averaged over a whole year, which reaches the United States? |
1.4 kJ, 0.18 kW/m2 |
|
What is terrestrial radiation? |
Terrestrial radiation is infrared radiation emitted by Earth’s surface. |
|
On a cold day your feet feel warmer on a rug than on a tile floor because a rug |
is a poorer conductor. |
|
Energy transfer by convection is primarily restricted to |
fluids |
|
At the same temperature, which has greater average speed in the air? |
very light molecules |
|
Sun’s radiant energy is composed of shorter wavelengths than Earth’s due to Sun’s greater |
Surface temperature |
|
What happens to the temperature of something that radiates energy without absorbing the same amount in return? |
it cools |
|
Objects that emit radiation relatively well |
absorb radiation relatively well. |
|
When an object absorbs as much as it radiates |
it remains at about the same temperature. |
|
If a pizza absorbs more energy than it emits, its temperature |
increases |
|
A liter of cold water will warm faster in sunlight in a |
black pot |
|
The temperature of outer space is |
about 2.7 kelvin |
|
A good absorber of radiation is a |
good emitter of radiation. |
|
A blueberry pie will be a net absorber of energy when its temperature is |
lower than its surroundings. |
|
If the composition of the upper atmosphere were altered to permit a greater amount of terrestrial radiation to escape, Earth would be |
cooler |
|
The heat we enjoy on a sunny day is due mainly to the Sun’s |
enormous size |
|
Substances absorb heat energy by the process of |
radiation. conduction. convection. |
|
Heat normally flows from objects of high |
temperature to objects of low temperature. |
|
When a hot object makes thermal contact with a cold object, the direction of |
internal energy flow is from hot to cold |
|
thermometric property |
measurable property that changes as temperature changes |
|
heat |
flow (transfer) of energy because a difference in temperature |
|
unit of heat energy |
1 calorie is how much heat is needed to raise the temperature of 1 gram of water by 1 degree celcius Q= m x c x change in T heat=mass x materialx change in Temperature |
|
thermal inertia |
how much heat (1 cal) per |
|
specific heat |
number of degrees of freedom |
|
ways molecules can have kinetic energy |
translation rotation vibration |
|
newtons law of cooling / heating |
rate of heat flow proportional to temperature difference |
|
3 methods of heat transfer |
conduction : neighbor atoms to neighbor atoms convection: neighborhoods of atoms move to new neighborhoods radiation: phone calls to other neighbors |
|
weins law |
frequency of the peak directly proportional to Temperature (kevlin) black body radiation |
|
temperature |
proportional to the average "translational" kinetic energy of random molecular motion (motion that carries the molecule from one place to another) rotational and vibrating dont define temperature |
|
internal energy |
the grand total of all the energies inside a substance there is more internal energy in the larger volume of water |
|
calorie |
the amount of heat required to change the temperature of 1 gram of water by 1 degree celscius |
|
insulators |
poor conductors that impede(delay) the transfer of heat examples: wool, wood, styrofoam,straw, paper, cork |
Share This
Flashcard
