Chapter 2 Flashcards
What is energy?
“the ability to do work”
Joule is the standard unit of energy
What is power?
Power is the rate at which energy is released, transferred, or received
What are the 2 forms of energy?
- Kinetic
2. Potential
What is kinetic energy?
energy being used
examples: light, heat, electrical power
What is potential energy?
stored energy
examples: batteries, firewood, food
What 3 ways is energy transferred?
- conduction
- convection
- Radiation
What is conduction?
- movement of heat through touch
- 2 items touching and transferring heat from 1 hot to a cold one
- conduction is most effective in solid materials but also is an important process in a very thin layer of air near earths
What is convection?
-the transfer of heat by mixing of a fluid
-over turning of a liquid or a gas
Examples: cold water on a stove to boil
What is buoyancy?
Warm air to rise
Of the 3 energy transfer mechanisms, _______ is only 1 that can be propagated without a transfer medium?
Radiation
The transfer of energy by radiation can occur through what?
Empty space/distance.
Example: the heat from fire
In radiation, quantity is associated with the height of the wave, or its _____?
Amplitude.
How much energy is coming at you.
This tells you what type of energy you are looking at?
Wavelength
What is the Stefan-Boltzmann law?
? The amount of energy emitted?
How do you convert C to Kelvin?
Kelvin temp= C + 273
Kelvin is NEVER a negative number
Boiling point of water in F, C, K?
212 F
100 C
373 K
Freezing point of water in F, C, K?
32 F
0 C
273 K
The wavelength that emits the most energy?
Weins Law
Hot temp (sun)= short wavelength Cole temp (earth)= long wavelength
The earths annual trip around the sun?
Revolution
Earths spinning motion?
Rotation
Rotation occurs every 24hrs around an imaginary line called?
Earths axis.
It’s tilted 23.5 from the sun and points at a distant star called Polaris
The northern hemisphere has its maximum tilt toward the sun on or about ________?
June 21- June/Summer solstice
Longest hours of daylight & most instense
23 1/2 N of equator
The Northern hemisphere has its minimum availability of solar radiation on?
December 21st- winter solstice
Longest night
Shortest light
In between the 2 solstices are what?
Equinox
March 21-spring
September 21-fall
12 hours of day and night
The point at which the sun rays are striking directly overhead?
Subpolar point
What is beam spreading?
It is the increase in the surface area over which radiation is distributed in response to a decrease of solar angle
Reason it is colder at the poles than it is at the tropics
