Ast 101 Midterm

Which of the following statements is false?

a) The planets all orbit in the same direction.
b) The planets all orbit in nearly the same plane.
c) The planets' orbits are all elliptical.
d) The planets all travel at the same average speed as each other in their orbits.
e) The planets all move at a faster speed when they are closer to the Sun than when they are further from the Sun.

The planets all travel at the same average speed as each other in their orbits.

Why is the average temperature on the surface of Venus hotter than the average temperature on the surface of Mercury?

a) Venus is closer to the Sun than Mercury.
b) Venus has more volcanic activity than Mercury.
c) Venus has a thick atmosphere that creates a greenhouse effect.
d) Venus is spinning more slowly on its axis than Mercury so it heats up more effectively.
e) Venus has slower winds than Mercury, so it isn't cooled as effectively.

Venus has a thick atmosphere that creates a greenhouse effect.

When is the moon closest to the Sun?

a) During a new moon.
b) During a waxing crescent.
c) During a waning crescent.
d) During a full moon.
e) During a quarter moon.

During a new moon.

Sandra sees a supernova explode in a galaxy that is two million light years away. Which of the following is true?

a) The light has travelled a distance of two million light years.

b) The light took two million years to reach her telescope.

c) The look-back time to the supernova is two million years.

d) She is seeing the supernova two million years after it actually exploded.

e) All of the Above

All of the above

In the geocentric model, what did epicycles explain?

a) Why each planet moves at a different speed from night to night.
b) Why the planets have retrograde motions.
c) Why there was no observable stellar parallax.
d) Why it does not feel like the earth is spinning.
e) Why the moon has phases.

Why the planets have retrograde motions.

Which of the following pairs of objects are closest in size to each other?

a) The Sun and Jupiter.
b) Saturn and Neptune.
c) Jupiter and Mercury.
d) The Solar System and the Milky Way galaxy.
e) The Earth and the Oort Cloud.

Saturn and Neptune

When does a solar eclipse happen?

a) When the moon crosses the ecliptic plane and it is a new moon.
b) When the moon crosses the ecliptic plane and it is a full moon.
c) Whenever the moon crosses the ecliptic plane.
d) When the moon passes through the shadow of the earth.
e) Whenever it is the fall or autumn equinox and the moon is at the furthest point in its orbit from Earth.

When the moon crosses the ecliptic plane and it is a new moon.

If the moon were twice as far away from us, tides on Earth would be _____, and occur ______

a) More extreme and Much more often.
b) Less extreme and About the same frequency
c) The same level and Much less often
d) Less extreme and Much more often.

Less extreme and About the same frequency

According to heliocentric models of the solar system, why do planets sometimes appear to"move backwards" with respect to background stars?

a) Because planets orbit in elliptical orbits
b) Because inner planets move faster than outer planets.
c) Because planets orbit in circles within circles
d) Because of the gravitational pull between planets.

Because inner planets move faster than outer planets.

Suppose Earth had a second moon with a 14-day orbital period. How many high tides would we experience per day?

a) There would always be two high tides.
b) Four, except when the two moons align.
c) Two, except when the two moons align.
d) There would always be four high tides.

Four, except when the two moons align.

When is the angular momentum of a planet the largest?

a) When it is further from the Sun
b) When it is closer to the Sun
c) During the equinoxes
d) It is always the same

It is always the same

f a wave suddenly slowed down to half its original speed but kept its same frequency, what would happen to its wavelength?

a) The wavelength would decrease by a factor of 2
b) The wavelength would decrease by a factor of 4
c) The wavelength would stay the same
d) The wavelength would increase by a factor of 2
e) The wavelength would increase by a factor of 4.

The wavelength would decrease by a factor of 2

In what range of wavelengths does the Sun's spectrum peak?

a) Microwave light
b) Optical light
c) Ultraviolet light
d) X-ray light

Optical light

How can we determine the temperature of the Sun based on its spectrum?

a) The specific absorption lines present tell us the Sun's temperature
b) The specific emission lines present tell us the Sun's temperature
c) The peak wavelength of the continuum spectrum (black body curve) tells us the Sun's temperature
d) The redshift of the continuum spectrum (blackbody curve) tells us the Sun's temperature
e) The blueshift of the continuum spectrum (blackbody curve) tells us the Sun'stemperature

The peak wavelength of the continuum spectrum (black body curve) tells us the Sun's temperature

The spectrum of a light source is observed to have absorption lines. What must be happening between the observer and the light source?

a) Atoms are emitting photons
b) Atoms are absorbing photons
c) Atoms are absorbing electrons
d) Atoms are emitting electrons

Atoms are absorbing photons

You observe the spectrum of a star today. In a few days, you observe it again and notice that the absorption lines in the stellar spectrum have moved towards shorter wavelengths. What happened?

a) The star is now moving away from us
b) The star is now moving towards us
c) The star is decreasing its size
d) The star is increasing its size

The star is now moving towards us

When looking at the spectrum of a star, if an absorption line associated with hydrogen is at a longer wavelength than what we see in the Sun:

a) The star is moving towards us
b) The star has more hydrogen than our Sun
c) The star is moving away from us
d) The star is not made of hydrogen

The star is moving away from us

An atom has three energy levels, 1 eV, 3 eV, and 4 eV. How can an electron move from the first energy level to the second energy level?

Image description: A grey shaded circle is enclosed by three concentric rings. Each ring represents an electron energy level ordered from the innermost ring being 1 eV and the outermost ring being 4 eV.

a) Absorb a photon of 3 eV
b) Emit a photon of 2 eV
c) Absorb a photon of 2 eV
d) Emit a photon of 3 eV
e) Absorb two photons of 1 eV each

Absorb a photon of 2 eV

Given that the Sun maintains hydrostatic equilibrium, what would happen if the core were toshrink, increasing its density?

a) The rate of nuclear fusion would be unaffected, and the increased gravity would make it keep shrinking until it turns into a black hole.
b) The rate of nuclear fusion would be unaffected, but the core would naturally bounce back to the equilibrium size.
c) The rate of nuclear fusion would increase, increasing the temperature and pressure. This would make the core expand back to the equilibrium size.
d) The rate of nuclear fusion would increase, increasing the temperature and decreasing the pressure. With less pressure, the core would expand back to the equilibrium size.
e) The rate of nuclear fusion would decrease, decreasing temperature and increasing pressure. This would make the core expand back to the equilibrium size.

The rate of nuclear fusion would increase, increasing the temperature and pressure. This would make the core expand back to the equilibrium size.

When nuclei fuse together in the core of the Sun, they release energy. Where does the energy come from?

a) Before they collided, they had high speed. The lost speed gets converted into energy.
b) A powerful chemical reaction occurs that produces excess energy.
c) The fusion produces radioactive uranium, which releases energy when it decays into lighter elements.
d) The total mass of the nuclei that fused together was greater than the mass of the resulting nucleus. The missing mass has been converted into energy.
e) After fusion, there are fewer nuclei, thereby decreasing the density of the core. This causes the core to shrink and heat up, releasing energy.

The total mass of the nuclei that fused together was greater than the mass of the resulting nucleus. The missing mass has been converted into energy.

A planet

a) must be smaller than the Earth

b) must clear its orbit

c) must be spherical

d) a + c

e) b + c

B + C (must clear its orbit + must be spherical)

Which of these lists of objects is correctly ordered from smallest to largest?

a) cell, atom, person, solar system, galaxy

b) person, galaxy, solar system, universe

c) earth, sun, Jupiter, galaxy

d) earth, sun, galaxy, universe

earth, sun, galaxy, universe

Which phrase is correct?

a) The sun is 8.3 light years away from the earth.

b) One astronomical unit is 8.3 light minutes.

c) It takes light 8.3 minutes to travel from the sun to the earth.

d) b + c

B+ C (One astronomical unit is 8.3 light minutes. It takes light 8.3 minutes to travel from the sun to the earth.)

Why would the constellations look the same no matter what planet in the Solar System we lived on?

a) Stars are very far away.

b) The angle between each planet's celestial equator and the ecliptic are the same.

c) Each planet precesses like a spinning top

d) The celestial pole points in the direction of Polaris.

e) Because my horoscope for today said the Sun passing through X is lucky for me.

Stars are very far away.

The ecliptic is:

a) the orbit of the Earth around the Sun,

b) the path of the Sun on the Celestial Sphere,

c) the projection of the Earth's equator into space,

d) the days of the year when the Sun shines equally on both hemispheres

the path of the Sun on the Celestial Sphere

A lunar eclipse happens when

a) the Earth is directly between the sun and the moon

b) the moon is directly between the sun and the earth

c) when the Earth comes directly between the sun and the moon, so that the earth's shadow falls on the moon

d) the Moon comes directly between the Sun and the Earth, so that the Moon's shadow falls on the Earth

when the Earth comes directly between the sun and the moon, so that the earth's shadow falls on the moon

I look up at the moon and notice that the moon is full. I jump in my rocket and head to the moon. When I land on the moon I look back at the Earth. What phase of the Earth do I see?

a) full

b) waxing quarter

c) waning gibbous

d) new

e) “phases” is a term only applied to the moon

New

Total lunar eclipses are more rare

a) than penumbral lunar eclipses

b) than full moons

c) than super moons

d) than all of the above

than all of the above

The moon looks red during a lunar eclipse because

a) sunlight is more red than blue

b) the sun's light is bent as it passes through the Earth's atmosphere

c) the sun's light reflects off the moon's atmosphere

d) it happens at night once the sun has set

the sun's light is bent as it passes through the Earth's atmosphere

Planets trace out an equal area in equal time means that

a) planet orbits all take the same time

b) planets move quickly at aphelion

c) planets move at different speeds at different places in their orbit

d) near perihelion a planet sweeps out an area that is very large but also wide

planets move at different speeds at different places in their orbit

The escape velocity from the surface of the Earth

a) depends on the distance that the object is from the centre of the Earth

b) depends on the mass of the object

c) depends on the temperature of the object

d) depends on the mass of the Earth

depends on the mass of the Earth

If the Sun did not affect them, tides would

a) be the same during every phase of the Moon

b) not exist

c) change with the Moon’s phase

d) only happen once per day.

be the same during every phase of the Moon

The Sun’s source of energy is due to ______ in its core:

a) Chemical Reactions,

b) Nuclear Fission,

c) Nuclear Fusion,

d) the compression of gas,

e) Albert Einstein

Nuclear Fission

Which of the following statements is true regarding the temperature of different coloured stars:

a) Red Stars are hotter than Blue Stars,

b) Blue stars are hotter than Yellow stars,

c) Yellow Stars are hotter than Blue Stars,

d) Red Stars are hotter than Yellow Stars

Blue stars are hotter than Yellow stars,

Put these types of light in order from longest wavelength to shortest:

a) Radio, Infrared, Visible, Gamma,

b) Radio, X-Ray, Microwave, UV,

c) Gamma, UV, Visible, Radio,

d) Infrared, UV, X-Ray, Radio

Radio, Infrared, Visible, Gamma,

Put these types of light in order from highest energy to lowest:

a) Radio, Infrared, Visible, Gamma,

b) Radio, X-Ray, Microwave, UV,

c) Gamma, UV, Visible, Radio,

d) Infrared, UV, X-Ray, Radio

Gamma, UV, Visible, Radio,

What statement is true regarding the wave-particle duality of light?

a) Light is both a wave and particle,

b) Light is a wave in vacuum but a particle in matter,

c) Light is a particle in vacuum but a wave in matter,

d) Light is either a wave or a particle, depending on the temperature

Light is both a wave and particle

In the spectrum of a star, the size and location of the blackbody peak tells us:

a) The star’s temperature,

b) The star’s structure,

c) The chemical composition of the star,

d) None of the above

The star’s temperature

When looking at the spectrum of a star, if the absorption line associated with Hydrogen is at a longer wavelength than what we see in the Sun:

a) The star is moving towards us,

b) The star is moving away from us,

c) the star is not moving,

d) the star has more Hydrogen than our Sun

The star is moving away from us

The clouds of material that stars form from mainly consists of:

a) Helium

b) Carbon monoxide,

c) Dust

d) Hydrogen

Hydrogen

Which is the correct ordering of objects, from smallest to largest?

(a) Earth, Human, Sun, Jupiter, Galaxy

(b) Human, Earth, Jupiter, Sun, Galaxy

(c) Galaxy, Human, Sun, Galaxy, Jupiter

(d) Jupiter, Sun, Galaxy, Earth, Human

(e) Human, Jupiter, Earth, Galaxy, Sun

Human, Earth, Jupiter, Sun, Galaxy

Which planet has the highest average surface temperature, and why?

(a) Mercury, because it is closest to the Sun

(b) Mercury, because of its dense carbon dioxide atmosphere

(c) Venus, because of its dense carbon dioxide atmosphere

(d) Mars, because of its red colour

(e) Jupiter, because it is so big

Venus, because of its dense carbon dioxide atmosphere

Which of the following is farthest from the Sun?

(a) Pluto

(b) Neptune

(c) an asteroid in the asteroid belt

(d) a comet in the Kuiper belt

(e) a comet in the Oort cloud

a comet in the Oort cloud

You are standing at the North Pole. Which way is Polaris, the North star?

(a) 30 degrees up, due West

(b) on the northern horizon

(c) directly overhead

(d) The answer depends on whether it's winter or summer.

(e) The answer depends on what time of day (or night) it is

directly overhead

Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?

(a) The Northern Hemisphere is closer to the Sun than the Southern Hemisphere.

(b) The Northern Hemisphere is "on top" of Earth and therefore receives more sunlight.

(c) The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight.

(d) The Northern Hemisphere is tilted away from the Sun and receives more indirect sunlight.

(e) It isn't: both hemispheres have the same seasons at the same time.

The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight.

In the Southern Hemisphere, when is the longest day of the year?

(a) Around June 21

(b) Around September 21

(c) Around December 21

(d) Around March 21

(e) Around February 21

Around December 21

What effect or effects would be most significant if the Moon's orbital plane were exactly the same as the

ecliptic plane?

(a) Solar eclipses would be much rarer.

(b) Solar eclipses would be much more frequent.

(c) Solar eclipses would last much longer.

(d) both A and C

(e) both B and C

Solar eclipses would be much more frequent.

The Ptolemaic model held that the Earth was the center of the Universe. How did the Ptolemaic model

explain the apparent retrograde motion of the planets?

(a) It held that sometimes the planets moved backward along their circular orbits.

(b) It held that the orbits of the planets are elliptical.

(c) It varied the motion of the celestial sphere so that it sometimes moved backward.

(d) It held that the apparent retrograde motion was due to a changing point of view caused by the location of

the sun.

(e) It held that the planets moved along small circles that moved on larger circles, also known as epicycles,

around Earth.

It held that the planets moved along small circles that moved on larger circles, also known as epicycles,

around Earth.

When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?

(a) Copernicus misjudged the distances between the planets.

(b) Copernicus misjudged the speeds at which the planets orbit the Sun.

(c) Copernicus placed the planets in the wrong order going outward from the Sun.

(d) Copernicus placed the Sun at the center but did not realize that the Moon orbits Earth.

(e) Copernicus used perfect circles for the orbits of the planets, whereas planets actually have elliptical orbits.

Copernicus used perfect circles for the orbits of the planets, whereas planets actually have elliptical orbits