Question 1

A spaceship approaches Earth at 0.9 times the speed of light and shines a powerful searchlight onto Earth.How fast will the photons from this searchlight be moving when they hit Earth?

Accepted Answer

At the spe

Question 2

An asteroid with an albedo of 0.1 and a comet with an albedo of 0.6 are orbiting at roughly the same distance from the Sun.How do their temperatures compare?

Accepted Answer

A) They both have the same temperature. 
B) The comet is hotter than the asteroid. 
C) The asteroid is hotter than the comet. 
D) You must know their sizes to compare their temperatures. 
E) You must know their compositions to compare their temperatures. 
A) They both have the same temperature. 
B) The comet is hotter than the asteroid. 
C) The asteroid is hotter than the comet. 
D) You must know their sizes to compare their temperatures. 
E) You must know their compositions to compare their temperatures.

Question 3

If a star has a peak wavelength of 290 nm,what is its surface temperature?

Accepted Answer

A) 1000 K 
B) 2000 K 
C) 5000 K 
D) 10,000 K 
E) 100,000 K 
A) 1000 K 
B) 2000 K 
C) 5000 K 
D) 10,000 K 
E) 100,000 K

Question 4

Which of these planets would be expected to have the highest average temperature?

Accepted Answer

A) a light-colored planet close to the Sun 
B) a dark-colored planet close to the Sun 
C) a light-colored planet far from the Sun 
D) a dark-colored planet far from the Sun 
E) There is not enough information to know which would be hotter. 
A) a light-colored planet close to the Sun 
B) a dark-colored planet close to the Sun 
C) a light-colored planet far from the Sun 
D) a dark-colored planet far from the Sun 
E) There is not enough information to know which would be hotter.

Question 5

A radio photon travels slower than a gamma ray photon.

Accepted Answer

A) True 
 B)False

Question 6

Imagine you observed three different stars: a red star,a blue star,and a yellow star.You are able to determine that each of these stars has the same radius.Answer each question below and explain how you know.
A: Which star is hottest?
B: Which star is the most luminous?
C: Which star is the brightest?

Accepted Answer

A: The blue one is the hottest because W

Question 7

The Doppler shift can be used to determine the _________ of an object.

Accepted Answer

A) energy 
B) temperature 
C) radial velocity 
D) color 
E) three-dimensional velocity 
A) energy 
B) temperature 
C) radial velocity 
D) color 
E) three-dimensional velocity

Question 8

Why do we see black lines in an absorption spectrum if the absorbed photons are (almost)instantaneously reemitted by the atoms in the cloud?

Accepted Answer

Originally all the light was traveling i

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

A red photon has a wavelength of 650 nm.An ultraviolet photon has a wavelength of 250 nm.The energy of an ultraviolet photon is _________ the energy of a red photon.

Accepted Answer

A) 2.6 times larger than 
B) 6.8 times larger than 
C) 2.6 times smaller than 
D) 6.8 times smaller than 
E) the same as 
A) 2.6 times larger than 
B) 6.8 times larger than 
C) 2.6 times smaller than 
D) 6.8 times smaller than 
E) the same as

Question 11

At what temperature does water freeze?

Accepted Answer

A) 0 K 
B) 32 K 
C) 100 K 
D) 273 K 
E) 373 K 
A) 0 K 
B) 32 K 
C) 100 K 
D) 273 K 
E) 373 K

Question 12

The period of a wave is inversely proportional to the frequency of that wave.

Accepted Answer

A) True 
 B)False

Question 13

Which of these objects would emit an absorption spectrum?

Accepted Answer

A) an incandescent light bulb 
B) a fluorescent light bulb 
C) an isolated hot gas cloud 
D) a hot,solid object 
E) a thin,cool gas cloud that lies in front of a hotter blackbody 
A) an incandescent light bulb 
B) a fluorescent light bulb 
C) an isolated hot gas cloud 
D) a hot,solid object 
E) a thin,cool gas cloud that lies in front of a hotter blackbody

Question 14

If the frequency of a beam of light were to increase,its period would _________ and its wavelength would _________?

Accepted Answer

A) decrease;increase 
B) increase;decrease 
C) increase;increase 
D) decrease;decrease 
E) stay the same;stay the same 
A) decrease;increase 
B) increase;decrease 
C) increase;increase 
D) decrease;decrease 
E) stay the same;stay the same

Question 15

Which formula denotes how the speed of light is related to its wavelength and frequency?

Accepted Answer

A) c = λf 
B) c = λ/f 
C) c = f/λ 
D) c = 1/λf 
E) There is no relationship between wavelength and frequency. 
A) c = λf 
B) c = λ/f 
C) c = f/λ 
D) c = 1/λf 
E) There is no relationship between wavelength and frequency.

Question 16

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 λ_peak = (2,900,000 nm

Question 17

The emission spectrum of a helium atom is identical to that of a carbon atom.

Accepted Answer

A) True 
 B)False

Question 18

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 19

What two factors control a planet's surface temperature if it has no atmosphere?

Accepted Answer

A planet's distance

Question 20

How do the wavelength and frequency of red light compare to the wavelength and frequency of blue light?

Accepted Answer

A) Red light has a longer wavelength and higher frequency than blue light. 
B) Red light has a longer wavelength and lower frequency than blue light. 
C) Red light has a shorter wavelength and higher frequency than blue light. 
D) Red light has a shorter wavelength and lower frequency than blue light. 
A) Red light has a longer wavelength and higher frequency than blue light. 
B) Red light has a longer wavelength and lower frequency than blue light. 
C) Red light has a shorter wavelength and higher frequency than blue light. 
D) Red light has a shorter wavelength and lower frequency than blue light.

Exam 5: Light

A spaceship approaches Earth at 0.9 times the speed of light and shines a powerful searchlight onto Earth.How fast will the photons from this searchlight be moving when they hit Earth?

An asteroid with an albedo of 0.1 and a comet with an albedo of 0.6 are orbiting at roughly the same distance from the Sun.How do their temperatures compare?

If a star has a peak wavelength of 290 nm,what is its surface temperature?

Which of these planets would be expected to have the highest average temperature?

A radio photon travels slower than a gamma ray photon.

The Doppler shift can be used to determine the _________ of an object.

Why do we see black lines in an absorption spectrum if the absorbed photons are (almost)instantaneously reemitted by the atoms in the cloud?

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

A red photon has a wavelength of 650 nm.An ultraviolet photon has a wavelength of 250 nm.The energy of an ultraviolet photon is _________ the energy of a red photon.

At what temperature does water freeze?

The period of a wave is inversely proportional to the frequency of that wave.

Which of these objects would emit an absorption spectrum?

If the frequency of a beam of light were to increase,its period would _________ and its wavelength would _________?

Which formula denotes how the speed of light is related to its wavelength and frequency?

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

The emission spectrum of a helium atom is identical to that of a carbon atom.

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

What two factors control a planet's surface temperature if it has no atmosphere?

How do the wavelength and frequency of red light compare to the wavelength and frequency of blue light?

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 Adornments Moons 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

If the frequency of a beam of light were to increase,its period would _ and its wavelength would _?