Chapter 5

Question 1

What are Wave Properties?

Answer 1

Wavelength, Frequency, Period, Amplitude, Speed (always constant)

Question 2

What is a Wavelength?

Answer 2

Distance between successive peaks (or troughs) if we freeze the wave at one moment in time.

Question 3

What is a Period?

Answer 3

A related idea is the amount of time it takes for the pattern to repeat if you stay in the same place.

Question 4

What is the Frequency?

Answer 4

The number of times the wave pattern will repeat (per second) if you stay at a fixed place - or how many waves (cycles) pass by per second. (Hertz)

Question 5

Period and Frequency relationship

Answer 5

Period = 1/Frequency

Question 6

Speed = ?

Answer 6

Distance/Time
Wavelength/Period
Wavelength * Frequency

Question 7

Speef of Light Equation

Answer 7

C = Wavelength * Frequency

Question 8

C = ?

Answer 8

3.0 x 10^8 m/s = 3.0 x 10^5 km/s = 300,000 km/s

Question 9

Wavelength Unit

Answer 9

m,nm,mm

Question 10

Frequency Unit

Answer 10

Hertz = Hz = 1/s

Question 11

Propagation of Light

Answer 11

Light spreads out as it goes away from its source (Energy decreasing)

Question 12

Inverse Square Law

Answer 12

The amount of light recieved by any given patch on the sphere gets diluted by the square of the distance from the source

Question 13

What is an Electromagnetic Wave?

Answer 13

The result is a wave of combined electric and magnetic fields.

Question 14

What is Radiation?

Answer 14

refers to any physical process in which energy passes from one place, through some intervening region to another place.

Question 15

What do we sometimes refer to light as?

Answer 15

Electromagnetic Radiation

Question 16

What is the Electromagnetic Spectrum?

Answer 16

When we split light into its components (rainbow).

Question 17

Different ranges of wavelengths on the electromagnetic spectrum (shortest to longest). Gamma, Ultra, X, Infrared, FM Radio, Microwave, AM Radio.

Answer 17

Gamma, X, Ultraviolet, Infrared, Microwave, FM, AM

Question 18

What color has the longest wavelength?

Answer 18

Red

Question 19

Energy Proportions

Answer 19

Higher Energy = Higher Frequency

Question 20

What light only reaches through the atmosphere?

Answer 20

Visible and Radio

Question 21

What objects emit radiation all the time?

Answer 21

All

Question 22

When charged particles move what is emitted?

Answer 22

light

Question 23

What does a higher temp mean?

Answer 23

more jostling and more light get emitted

Question 24

All motion stops at what temp?

Answer 24

0 K

Question 25

What is thermal radiation?

Answer 25

is emitted by an opaque object, it shows emitted light intensity as a function of wavelength.

Question 26

What is determined only by temp?

Answer 26

The emitted spectrum

Question 27

What is Wien's Law?

Answer 27

The higher the temp, the shorter the wavelength of peak emission. The hotter the object the bluer it looks.

Question 28

What is the wavelength peak?

Answer 28

It is the point of the wavelength at which the objects emit the most energy.

Question 29

What is Stefan-Boltzmann Law?

Answer 29

Total (summed over all wavelengths) energy emitted is proportional to the 4th power of temp (note heigh of curves)

Question 30

What is Flux?

Answer 30

Energy per second per unit area

Question 31

What is a continuous spectrum?

Answer 31

When we pass a beam of white sunlight through a prism, we see a rainbow-colored band of light.

Question 32

What is dispersion?

Answer 32

Violet light is bent more than red light, causing the different wavelengths of light to spread out.

Question 33

What is due to atoms in a thin gas?

Answer 33

Emission and Absorption

Question 34

What is Emission?

Answer 34

Mostly dark some color.

Question 35

What is Absorption?

Answer 35

Mostly color some dark spots.

Question 36

Why do electrons absorb energy?

Answer 36

By absorbing energy they can more to energy levels further from the nucleaus.

Question 37

How do electrons absorb radiation?

Answer 37

To leaping up

Question 38

How do electrons emit radiation?

Answer 38

By falling down

Question 39

What is the Doppler effect?

Answer 39

The motion of a light source toward or away form us changes our perception of the wavelength of the waves reaching us.

Question 40

Light approaching objects is what?

Answer 40

blueshifted (shorter wavelengths)

Question 41

Light receding from objects is what?

Answer 41

redshifted (longer wavelengths)

Question 42

Why does the sky look blue?

Answer 42

Blue wavelengths from the sun scatter across the sky and spread out till they eventually reach your eye.