Astronomy Exam 2 MTSU

Review for exam and final exam

Used epicycles to explain planetary motions

Claudius Ptolemy

The astronomer who revolutionized the system for describing the motions of planets by placing the Sun at the center of the solar system

Nicholas Copernicus

First observed phases for an object other than the moon

Galileo Galilei

Made excellent observations of Mars that led Kepler to deduce his model of planetary motion

Tycho Brahe

A philosopher who thought that everything was perfectly spherical and that planets and stars orbited the earth in concentric spheres

Aristotle

Discovered that Jupiter had its own orbiting moon system

Galileo Galilei

Compared to the energy of a photon of visible light, the energy of a photon of X-rays is

A. Much lower
B. Much higher
C. About the same

B. Much higher

What is the ONE-WAY light travel time from Earth to Jupiter (at the minimum Earth-Jupiter distance of about 4 AU)? [Approximate light travel time from the sun to Earth= 8 minutes]

A. 4 hours
B. 65 minutes
C. 4 minutes
D. 32 minutes

D. 32 minutes

Which star in the diagram appears yellowish in color?

A. One (1)
B. Two (2)
C. Three (3)

B. Two (2)

If all the other star properties are the same except the temperature, which star in the diagram appears the dimmest?

A. One (1)
B. Two (2)
C. Three (3)

C. Three (3)

According to Kepler's second law, where does an object move fastest in its orbit?

A. 1
B. 2
C. 3
D. 4

D. 4

Position 1 in the diagram is called

A. the ecliptic
B. the aphelion point
C. perihelion point
D. the orbit period

B. the aphelion point

If the Earth were moved to an average distance of 2 AU from the sun, what would be the approximate length of the year?

A. 1.5 years
B. 3 years
C. 4 years
D. 8 years

B. 3 years

According to Kepler's 1st Law, what is the shape of a planetary orbit?

A. Circular
B. Rectangular
C. Elliptical

C. Elliptical

A measure of the time it takes to complete the elliptical orbit of a planet is the

A. Semi-major axis
B. Point of perihelion
C. Eccentricity
D. Period of the orbit
E. Tilt of the orbit plane

D. Period of the orbit

If you increase the temperature of a blackbody by two (2) times the wavelength at which the maximum intensity is observed is changed by

A. One-fourth
B. Sixteen
C. Two
D. One-half

D. One-half

Two stars, X and Y are similar in all ways (same distance size) except for temperature/color. Star X is hotter than Star Y. According to Stefan-Boltzmann's Law, which star is brighter?

A. Star X
B. Star Y
C. Both are equally bright

A. Star X

Vega has a higher surface temperature than the sun; therefore (with IR= infrared and UV= ultraviolet)

A. Vega emits more IR and more UV flux than the sun
B. Vega emits less IR and more UV flux than the sun
C. Vega emits more IR and less UV flux than the sun
D. Vega emits less IR and less UV flux than the sun

A. Vega emits more IR and more UV flux than the sun

Use Kepler's 3rd Law of motion and calculate the approximate orbit period of an asteroid if the semimajor axis a= 4 AU

A. 2 years
B. 3 years
C. 8 years
D. 1.25 years

C. 8 years

Which Jovian planet has the longest year (orbit period)?

A. Jupiter
B. Saturn
C. Uranus
D. Neptune

D. Neptune

Which one of the following statements is true?

A. Visible light takes up only a very small part of the total range of wavelengths in the electromagnetic spectrum
B. Visible light takes up most (but not all)of the total range of wavelengths in the electromagnetic spectrum
C. Visible light takes up all of the electromagnetic spectrum
D. Visible light is not part of the electromagnetic spectrum

A. Visible light takes up only a very small part of the total range of wavelengths in the electromagnetic spectrum

How fast does an ultraviolet (UV) light wave travel compared to the speed of visible light?

A. Slower than the speed of light
B. Equal to the speed of light
C Faster than the speed of light

B. Equal to the speed of light

The energy of a photon of light is directly proportional to the wavelength of the radiation. [Hint: look at your equations.]

A. True
B. False

B. False

Which of the following has the shortest wavelength in the electromagnetic spectrum?

A. blue light
B. infrared waves
C. gamma rays
D. radion waves

C. gamma rays

If you added all the colors of light from a rainbow what "color" is seen?

A. Blue
B. Red
C. Yellow
D. White
E. Black

D. White

What is the wavelength of a radio wave with frequency 3x10^8 Hz?

A. 1m
B. 10m
C. 100m
D. 1000m

A. 1m

The Kepler model of the solar system is

A. Sun-centered with elliptical planetary orbits
B. Earth-centered, with Sun, Moon, and planets moving in ellipses in the sky
C. Sun-centered, with planets moving in perfect circles around it
D. Earth-centered, with planets describing epicycles in the sky

A. Sun-centered with elliptical planetary orbits

The geocentric model of the universe holds that the Sun is at the center of the universe.

A. True
B. False

B. False

Which astronomer's solar system model is represented in this figure?

A. Galileo
B. Ptolemy
C. Aristotle
D. Copernicus
E. Tycho

D. Copernicus

Galileo's discovery of the moons of Jupiter was shocking because it showed those who believed Earth to be at the center of the Universe that

A. Not every celestial object orbits Earth
B. Planets can have more than one moon
C. Jupiter does not orbit the Sun
D. Gravity only works at Jupiter

A. Not every celestial object orbits Earth

Pieces of metal are heated by varying amounts in a flame. The hottest of the these is the one that shows which color most prominently?

A. red
B. blue
C. yellow
D. black

B. blue

If you increase the temperature of a blackbody by TWO times the energy emitted (Flux) by, that star would increase or decrease by how many times?

A. Increase by 4 times
B. Decrease by 4 times
C. Increase by 9 times
D. Decrease by 64 times
E. Increase by 16 times

E. Increase by 16 times

Which blackbody curve in the figure would best represent a blue-colored star?

A. 7500 K star
B. 6000 K star
C. 4500 K star

A. 7500 k star

According to Wein's law and Stefan-Boltzmann's law, how does the color and intensity change as the temperature of a hot object increases?

A. It gets bluer and dimmer
B. It gets redder and brighter
C. It gets redder and dimmer
D. It gets bluer and brighter

D. It gets bluer and brighter

A light source's velocity relative to us, causes a change in the observation frequency (or wavelength) of a wave. What is this?

A. The Period Effect
B. The Speed Phenomena
C. The Doppler Effect
D. The Energy Principle

C. The Doppler Effect

Kepler's 3rd Law states that P^2 = a^3.What does this law mean?

A. The sun is at the center of planetary orbits
B. All planetary orbits are ellipses
C. Slowly moving planets are close to the sun
D. A planet moves more rapidly when near the sun than when farther away
E. Planets close to the sun have shorter orbital periods than those further away

E. Planets close to the sun have shorter orbital periods than those further away

The speed of a planet orbiting the sun depends on the planet's position in its orbit.

A. True
B. False

A. True

If Earth's orbit distance around the sun were twice (2 times) as large as it is now, how would the time to complete one orbit change?

A. Less than two times
B. Exactly two times longer
C. More than two times longer

C. More than two times longerWhat

What color is a sodium lamp?

A. Bluish
B. Greenish
C. Yellowish
D. Orange-red

C. Yellowish

Imagine an emission spectrum produced by a container of hydrogen gas. Changing the gas from hydrogen to helium will change the colors of the lines occurring in the spectrum.

A. True
B. False

A. True

If the light creating spectrum 2 were coming only from the gas cloud, what would be seen on the spectrum

A. All colors are seen
B. Only a few colored lines are seen
C. It would look all black
D. All colors would be seen with a few dark lines
E. It would look all white

B. Only a few colored lines are seen

Which spectrum would show absorption lines?

A. Spectrum 1
B. Spectrum 2
C. Spectrum 3

C. Spectrum 3

Spectrum 1 is called a(n) _______ spectrum.

A. Continuous
B. Emission
C. Absorption

A. Continuous

As you drive away from a radio transmitter, the radio signal you receive from the station is shifted to longer wavelengths.

A. True
B. False

A. True

If Earth were to be moved to a distance of 2 AU from the sun, how much stronger or weaker would be the sun's gravitational force on earth?

A. 2 times weaker
B. 2 times stronger
C. 4 times weaker
D. 4 time stronger
E. 10 times weaker

C. 4 times weaker

See the figure. When moving to a higher energy level in an atom, an electron ________ a photon of a specific energy.

A. emits
B. absorbs
C. vaporizes
D. creates

B. absorbs

Astronomers analyze starlight to determine a star's

A. Composition
B. Coordinates
C. Size
D. Distance

A. Composition

Suppose that a planet of 5 times the mass of Earth were orbiting the Sun at the same distance as Earth (AU). The gravitational force on this planet due to the sun would be

A. 1/5 of that on Earth due to the sun
B. 25 times that on Earth due to the sun
C. 5 times that on Earth due to the sun
D. 1/25 of that on Earth due to the sun

C. 5 times that on Earth due to the sun

If the Moon's mass is doubled, but Earth's mass remained the same and the Earth-Moon distance remained the same, how much stronger or weaker would be the gravitational force between them?

A. 2 times weaker
B. 2 times stronger
C. 4 times weaker
D. 4 times stronger
E. 10 times weaker

B. 2 times stronger

If the Moon were suddenly moved to one-half (1/2 times) its normal distance from Earth, then the Moon's gravitational effect on Earth would be

A. 2 times as large
B. 2 times as small
C. 4 times as large
D. No change on the effect of gravity
E. 4 times as small

C. 4 times as large