Chapter 2

Question 1

What is energy?

Answer 1

“the ability to do work”

Joule is the standard unit of energy

Question 2

What is power?

Answer 2

Power is the rate at which energy is released, transferred, or received

Question 3

What are the 2 forms of energy?

Answer 3

1. Kinetic

2. Potential

Question 4

What is kinetic energy?

Answer 4

energy being used

examples: light, heat, electrical power

Question 5

What is potential energy?

Answer 5

stored energy

examples: batteries, firewood, food

Question 6

What 3 ways is energy transferred?

Answer 6

1. conduction
2. convection
3. Radiation

Question 7

What is conduction?

Answer 7

• 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

Question 8

What is convection?

Answer 8

-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

Question 9

What is buoyancy?

Answer 9

Warm air to rise

Question 10

Of the 3 energy transfer mechanisms, _______ is only 1 that can be propagated without a transfer medium?

Answer 10

Radiation

Question 11

The transfer of energy by radiation can occur through what?

Answer 11

Empty space/distance.

Example: the heat from fire

Question 12

In radiation, quantity is associated with the height of the wave, or its _____?

Answer 12

Amplitude.

How much energy is coming at you.

Question 13

This tells you what type of energy you are looking at?

Answer 13

Wavelength

Question 14

What is the Stefan-Boltzmann law?

Answer 14

? The amount of energy emitted?

Question 15

How do you convert C to Kelvin?

Answer 15

Kelvin temp= C + 273

Kelvin is NEVER a negative number

Question 16

Boiling point of water in F, C, K?

Answer 16

212 F
100 C
373 K

Question 17

Freezing point of water in F, C, K?

Answer 17

32 F
0 C
273 K

Question 18

The wavelength that emits the most energy?

Answer 18

Weins Law

Hot temp (sun)= short wavelength 
Cole temp (earth)= long wavelength

Question 19

The earths annual trip around the sun?

Answer 19

Revolution

Question 20

Earths spinning motion?

Answer 20

Rotation

Question 21

Rotation occurs every 24hrs around an imaginary line called?

Answer 21

Earths axis.

It’s tilted 23.5 from the sun and points at a distant star called Polaris

Question 22

The northern hemisphere has its maximum tilt toward the sun on or about ________?

Answer 22

June 21- June/Summer solstice
Longest hours of daylight & most instense
23 1/2 N of equator

Question 23

The Northern hemisphere has its minimum availability of solar radiation on?

Answer 23

December 21st- winter solstice
Longest night
Shortest light

Question 24

In between the 2 solstices are what?

Answer 24

Equinox
March 21-spring
September 21-fall
12 hours of day and night

Question 25

The point at which the sun rays are striking directly overhead?

Answer 25

Subpolar point

Question 26

What is beam spreading?

Answer 26

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