Question 1

If you were driving down a deserted country road and you saw a light in the distance, what would you need to measure or know about it in order to calculate how far away it was?

Accepted Answer

You would need to kn

Question 2

An emission line is produced when an atom absorbs a photon of a specific energy.

Accepted Answer

A) True 
 B)False

Question 3

You observe the spectrum of two stars. A section of these spectra are shown below. The spectra are different because star A is:

Accepted Answer

A)  cooler than star B 
B)  farther away from us than star B 
C)  moving toward us faster than star B 
D)  made of different elements than star B 
E)  larger than star B 
A)  cooler than star B 
B)  farther away from us than star B 
C)  moving toward us faster than star B 
D)  made of different elements than star B 
E)  larger than star B

Question 4

If you want a blackbody's peak wavelength to be cut in half, by how much do you need to increase its temperature?

Accepted Answer

Wien's law states that @#LAT-DLM&_peak@#LAT-DLM&(2

Question 5

As a blackbody becomes hotter, it also becomes _________ and _________.

Accepted Answer

A)  more luminous; redder 
B)  more luminous; bluer 
C)  less luminous; redder 
D)  less luminous; bluer 
E)  more luminous; stays the same color 
A)  more luminous; redder 
B)  more luminous; bluer 
C)  less luminous; redder 
D)  less luminous; bluer 
E)  more luminous; stays the same color

Question 6

Light is:

Accepted Answer

A)  a wave 
B)  a particle 
C)  both a particle and a wave 
D)  neither a particle nor a wave 
A)  a wave 
B)  a particle 
C)  both a particle and a wave 
D)  neither a particle nor a wave

Question 7

What wavelengths of light can the human eye see?

Accepted Answer

A)  3.8 $\mu$m to 7.5 $\mu$m 
B)  3.8 nm to 7.5 nm 
C)  380 cm to 750 cm 
D)  380 nm to 750 nm 
E)  3.8 m to 7.5 m 
A)  3.8 $\mu$m to 7.5 $\mu$m 
B)  3.8 nm to 7.5 nm 
C)  380 cm to 750 cm 
D)  380 nm to 750 nm 
E)  3.8 m to 7.5 m

Question 8

Figure 1
-Describe, in your own words, the fundamental problem with the Bohr model of the atom. (That is, why doesn't an electron orbit a nucleus like a planet does the Sun?)

Accepted Answer

In this model, the electron is constantl

Question 9

Compare two blackbody objects, one at 200 K and one at 400 K. How much larger is the flux from the 400 K object, compared to the flux from the 200 K object?

Accepted Answer

A)  two times larger 
B)  four times larger 
C)  eight times larger 
D)  sixteen times larger 
E)  They have the same flux. 
A)  two times larger 
B)  four times larger 
C)  eight times larger 
D)  sixteen times larger 
E)  They have the same flux.

Question 10

What is the difference between visible light and X-rays?

Accepted Answer

A)  Speed; X-rays go faster than visible light. 
B)  Speed; X-rays go slower than visible light. 
C)  Wavelength; X-rays have a shorter wavelength than visible light. 
D)  Wavelength; X-rays have a longer wavelength than visible light. 
E)  X-rays are made up of particles, while visible light is made up of waves. 
A)  Speed; X-rays go faster than visible light. 
B)  Speed; X-rays go slower than visible light. 
C)  Wavelength; X-rays have a shorter wavelength than visible light. 
D)  Wavelength; X-rays have a longer wavelength than visible light. 
E)  X-rays are made up of particles, while visible light is made up of waves.

Question 11

Star C and star D have the same luminosity. Star C is twice as far away from Earth as star D. How do the brightnesses of stars C and D compare?

Accepted Answer

A)  Star C appears four times as bright as star D. 
B)  Star C appears twice as bright as star D. 
C)  Star D appears twice as bright as star C. 
D)  Star D appears four times as bright as star C. 
E)  Stars C and D appear equally bright. 
A)  Star C appears four times as bright as star D. 
B)  Star C appears twice as bright as star D. 
C)  Star D appears twice as bright as star C. 
D)  Star D appears four times as bright as star C. 
E)  Stars C and D appear equally bright.

Question 12

If Saturn has a semimajor axis of 10 AU and an albedo of 0.7, what is its expected temperature?

Accepted Answer

A)  130 K 
B)  15 K 
C)  35 K 
D)  170 K 
E)  65 K 
A)  130 K 
B)  15 K 
C)  35 K 
D)  170 K 
E)  65 K

Question 13

If the wavelength of a beam of light were to double, how would that affect its frequency?

Accepted Answer

A)  The frequency would be four times larger. 
B)  The frequency would be two times larger. 
C)  The frequency would be two times smaller 
D)  The frequency would be four times smaller. 
E)  There is no relationship between wavelength and frequency. 
A)  The frequency would be four times larger. 
B)  The frequency would be two times larger. 
C)  The frequency would be two times smaller 
D)  The frequency would be four times smaller. 
E)  There is no relationship between wavelength and frequency.

Question 14

The luminosity of an object is independent of its distance from you.

Accepted Answer

A) True 
 B)False

Question 15

The emission lines of a given atom occur at the exact same energies as that atom's absorption lines.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following factors does NOT directly influence the temperature of a planet?

Accepted Answer

A)  the luminosity of the Sun 
B)  the distance of the planet from the Sun 
C)  the albedo of the planet 
D)  the size of the planet 
E)  the atmosphere of the planet 
A)  the luminosity of the Sun 
B)  the distance of the planet from the Sun 
C)  the albedo of the planet 
D)  the size of the planet 
E)  the atmosphere of the planet

Question 17

Why do some stars in the sky appear blue, while other stars appear red?

Accepted Answer

A)  The red stars are hotter on their surfaces than the blue stars. 
B)  The blue stars are hotter on their surfaces than the red stars. 
C)  The blue stars are closer to us than the red stars. 
D)  The red stars are closer to us than the blue stars. 
E)  The blue stars are moving away from us faster than the red stars. 
A)  The red stars are hotter on their surfaces than the blue stars. 
B)  The blue stars are hotter on their surfaces than the red stars. 
C)  The blue stars are closer to us than the red stars. 
D)  The red stars are closer to us than the blue stars. 
E)  The blue stars are moving away from us faster than the red stars.

Question 18

Einstein showed that the _________ could be explained if photons carried quantized amounts of energy.

Accepted Answer

A)  warping of space and time 
B)  Heisenberg uncertainty principle 
C)  photoelectric effect 
D)  theory of special relativity 
E)  Bohr model of the atom 
A)  warping of space and time 
B)  Heisenberg uncertainty principle 
C)  photoelectric effect 
D)  theory of special relativity 
E)  Bohr model of the atom

Question 19

Cooler objects radiate more of their total light at shorter wavelengths than hotter objects.

Accepted Answer

A) True 
 B)False

Question 20

Name four physical properties of an object that we can determine by analyzing the radiation that it emits, and briefly describe how these properties are determined. Cite the names of any laws that apply.

Accepted Answer

We can learn the following: (1) measure

Exam 5: Light

If you were driving down a deserted country road and you saw a light in the distance, what would you need to measure or know about it in order to calculate how far away it was?

An emission line is produced when an atom absorbs a photon of a specific energy.

You observe the spectrum of two stars. A section of these spectra are shown below. The spectra are different because star A is:

If you want a blackbody's peak wavelength to be cut in half, by how much do you need to increase its temperature?

As a blackbody becomes hotter, it also becomes _________ and _________.

Light is:

What wavelengths of light can the human eye see?

Figure 1 -Describe, in your own words, the fundamental problem with the Bohr model of the atom. (That is, why doesn't an electron orbit a nucleus like a planet does the Sun?)

Compare two blackbody objects, one at 200 K and one at 400 K. How much larger is the flux from the 400 K object, compared to the flux from the 200 K object?

What is the difference between visible light and X-rays?

Star C and star D have the same luminosity. Star C is twice as far away from Earth as star D. How do the brightnesses of stars C and D compare?

If Saturn has a semimajor axis of 10 AU and an albedo of 0.7, what is its expected temperature?

If the wavelength of a beam of light were to double, how would that affect its frequency?

The luminosity of an object is independent of its distance from you.

The emission lines of a given atom occur at the exact same energies as that atom's absorption lines.

Which of the following factors does NOT directly influence the temperature of a planet?

Why do some stars in the sky appear blue, while other stars appear red?

Einstein showed that the _________ could be explained if photons carried quantized amounts of energy.

Cooler objects radiate more of their total light at shorter wavelengths than hotter objects.

Name four physical properties of an object that we can determine by analyzing the radiation that it emits, and briefly describe how these properties are determined. Cite the names of any laws that apply.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

As a blackbody becomes hotter, it also becomes _ and _.