Exam 2 (chapter 3 terms)

Question 1

energy

Answer 1

the capacity for doing work

Question 2

law of energy conservation

Answer 2

energy is neither created nor destroyed, but can change from one form to another; also known as the first law of thermodynamics

Question 3

electromagnetic radiation

Answer 3

energy in the form of waves that have both electrical and magnetic properties and travel through gasses, liquids, and solids, and occur even in a vacuum. All objects emit all forms of electromagnetic radiation, although each object emits its peak radiation at a certain wavelength within the electromagnetic spectrum

Question 4

electromagnetic spectrum

Answer 4

range of electromagnetic radiation types arranged by wavelength or by wave frequency of both. Although the electromagnetic spectrum is continuous, different names are assigned to different segments. These segments extend from the longest wavelength (lowest frequency) radio waves through microwaves, infrared radiation, visible radiation, ultraviolet radiation, X-rays, to the shortest wavelength (highest frequency) gamma radiation

Question 5

Wavelength

Answer 5

the distance between successive wave crests (or equivalently, wave troughs)

Question 6

wave frequency

Answer 6

number of crests or troughs of a wave that pass a given point in a specific period of time, usually one second

Question 7

Visible radiation

Answer 7

electromagnetic radiation that is perceptible to the human eye with wavelengths ranging from about 0.40 (violet) to 0.70 (red). Visible radiation has wavelengths shorter than infrared radiation but longer than ultraviolet radiation

Question 8

Infrared radiation

Answer 8

electromagnetic radiation at wavelengths ranging from 0.8 (near-infrared) to about 0.1 mm (far infrared). IR radiation has wavelengths shorter than microwaves and longer than visible red light; most objects in the Earth-atmosphere system have their peak emission in the infrared

Question 9

Blackbody

Answer 9

a hypothetical “body” that absorbs all electromagnetic radiation that incident on it at every wavelength and emits all radiation at every wavelength; no radiation is reflected or transmitted. The “body” must be large compared to the wavelength of incident radiation

Question 10

Wien’s Displacement Law

Answer 10

a radiation law whereby the wavelength of maximum emission by a blackbody is inversely proportional to its absolute temperature (in kelvins). For example, hot objects (such as the Sun) emit peak radiation at relatively short wavelengths, whereas cold objects (such as the Earth-atmosphere system) emit peak radiation at longer wavelengths

Question 11

Stefan-Boltzmann Law

Answer 11

a radiation law that states that the total energy radiated by a blackbody at all wavelengths is directly proportional to the fourth power of the absolute temperature )in kelvins) of the body. For example, the Sun’s energy output per square meter is about 190,000 times that of the Earth-atmosphere system

Question 12

Inverse square Law

Answer 12

intensity of radiation emitted by a point source (e.g., the Sun) decreases as the inverse square of distance traveled

Question 13

Global radiative equilibrium

Answer 13

the balance between net incoming solar radiation and infrared radiation emitted to space by the Earth-atmosphere system