Deck 3: Motion of Astronomical Bodies

Question 1

Retrograde motion is seen when ________ due to Earth's motion.

A) stars change their position in the sky with respect to background stars
B) stars rise in the west and set in the east
C) planets rise in the west and set in the east
D) planets change the direction in which they move across the night sky
E) planets orbit the Sun in the opposite direction

Answer 1

planets change the direction in which they move across the night sky

Question 2

At the center of the geocentric model of the Solar System is

A) the Sun.
B) the Moon.
C) Earth.
D) Venus.
E) Jupiter.

Answer 2

Earth.

Question 3

When Earth catches up to a slower-moving outer planet and passes it like a faster runner overtaking a slower runner in an outside lane, the planet

A) exhibits retrograde motion.
B) slows down because it feels Earth's gravitational pull.
C) decreases in brightness as it passes through Earth's shadow.
D) moves into a more elliptical orbit.
E) exhibits prograde motion.

Answer 3

exhibits retrograde motion.

Question 4

How did Ptolemy "fix" the geocentric system?

A) He introduced retrograde motion.
B) He introduced prograde motion.
C) He moved the Sun to the center.
D) He introduced epicycles.
E) He introduced Earth's motion.

Question 5

Nicolaus Copernicus is credited with creating the first detailed mathematical model of

A) the tilt of the Earth's rotational axis.
B) a heliocentric solar system.
C) lunar eclipses.
D) epicycles.
E) a geocentric solar system.

Question 6

Based on the figure below, an inferior planet would have its greatest angular separation from the Sun and would therefore be most easily visible at

A) inferior conjunction.
B) superior conjunction.
C) only greatest eastern elongation.
D) only greatest western elongation.
E) at either greatest eastern or western elongation.

Question 7

Which of the following are the inferior planets?

A) only Mercury
B) Mercury and Mars
C) Mercury and Venus
D) only Mars
E) Mercury, Mars, and Pluto

Question 8

________ was the first person to introduce a mathematical heliocentric model of the Solar System from which accurate predictions could be made of planets' positions.

A) Nicolaus Copernicus
B) Tycho Brahe
C) Johannes Kepler
D) Galileo Galilei
E) Isaac Newton

Question 9

Based on the figure below, a superior planet would be seen high overhead at midnight

A) when at opposition.
B) when at eastern quadrature.
C) when at conjunction.
D) when at western quadrature.
E) throughout its orbit.

Question 10

In the ________ model of the Solar System, ________ motion is only an apparent, not a real, motion.

A) geocentric; retrograde
B) heliocentric; retrograde
C) geocentric; prograde
D) heliocentric; prograde
E) Galilean; prograde

Question 11

Who of the following was NOT a proponent of the heliocentric model of the solar system?

A) Galileo
B) Copernicus
C) Newton
D) Ptolemy
E) Aristarchus

Question 12

Based on the figure below, a superior planet at opposition

A) would rise at noon and set at midnight.
B) would rise at midnight and set at noon.
C) would rise at sunset and set at sunrise.
D) would rise at sunrise and set at sunrise.
E) would rise at 8 P.M.and set at 8 A.M.

Question 13

The time it takes for a planet to come back to the same position relative to the Sun is called its ________ period.

A) synodic
B) sidereal
C) heliocentric
D) geocentric
E) prograde

Question 14

Astronomers argued that the heliocentric model of the Solar System was simpler than the geocentric model, based on

A) the observation that the planets do not move relative to the background stars.
B) the fact that the Moon orbits Earth.
C) the fact that the Sun is more massive than Earth.
D) the observed retrograde motions of the planets.
E) the observed timing of lunar and solar eclipses.

Question 15

Based on his observations of the planets, Copernicus calculated the relative distance of the planets from the Sun using the heliocentric model.These distances were

A) 10 times too large.
B) exactly correct.
C) close to the correct values, with errors less than 0.5 astronomical unit (AU).
D) accurate, but not as accurate as Ptolemy's values.
E) two times too small.

Question 16

The Copernican model of the solar system has planets traveling on

A) noncircular elliptical orbits.
B) spiral orbits.
C) perfectly circular orbits.
D) dozens of epicycles.
E) straight lines through curved space.

Question 17

A superior planet is one that is

A) smaller than Earth.
B) larger than Earth.
C) closer to the Sun than Earth.
D) farther from the Sun than Earth.
E) made of heavier materials than Earth.

Question 18

When the Sun, Earth, and a planet all lie along a straight line, the planet is at

A) quadrature.
B) only opposition.
C) only greatest elongation.
D) only conjunction.
E) either opposition or conjunction.

Question 19

Which of the following are superior planets?

A) Mars
B) Earth and Venus
C) Venus, Mars, Jupiter, and Saturn
D) Earth, Jupiter, and Saturn
E) Mars, Jupiter, and Saturn

Question 20

An inferior planet is one that is

A) smaller than Earth.
B) larger than Earth.
C) closer to the Sun than Earth.
D) farther from the Sun than Earth.
E) made of lighter materials than Earth.

Question 21

Kepler's third law is a relationship between an orbiting object's

A) gravitational force and mass.
B) acceleration and mass.
C) velocity and period.
D) period and semimajor axis.
E) semimajor axis and velocity.

Question 22

During a certain comet's orbit around the Sun, its closest distance to the Sun is 0.6 AU, and its farthest distance from the Sun is 35 AU.At what distance will the comet's orbital velocity be the largest?

A) 35 AU
B) 17.8 AU
C) 1.2 AU
D) 0.6 AU
E) The comet's velocity is constant no matter what its distance is.

Question 23

The fact that Kepler's heliocentric model of the Solar System predicted ________ more easily and accurately than the geocentric model is an illustration of how scientific theories evolve by the scientific method.

A) solar eclipses
B) lunar eclipses
C) retrograde motion of planets
D) prograde motion of planets
E) the duration of the seasons

Question 24

Kepler's third law for our Solar System can be expressed mathematically as

A) P $\infty$ A.
B) P² $\infty$ A².
C) P² $\infty$ A³.
D) P³ $\infty$ A².
E) P $\infty$ A².

Question 25

If the synodic period of Mars is observed from Earth to be 2.1 years, what is the sidereal period of Mars?

A) 5.3 years
B) 0.47 years
C) 1.9 years
D) 3.4 years
E) 0.69 years

Question 26

The amount of time a planet takes to orbit the Sun once, from that planet's perspective, is called its ________ period.

A) synodic
B) sidereal
C) prograde
D) retrograde
E) geocentric

Question 27

The distance between the foci when the eccentricity equals zero is

A) equal to the semimajor axis.
B) equal to the semiminor axis.
C) half the semimajor axis.
D) zero.
E) infinite.

Question 28

In the figure below, a planet orbits the Sun.The line connecting the planet and Sun sweeps out three areas labeled A, B, and C, during three different time intervals.If the duration of the time intervals are the same (meaning t₂ - t₁ = t₄ -t₃ = t₆ - t₅), how are the sizes of these areas related?

A) A $\gt$ B $\gt$ C
B) C $\gt$ B $\gt$ A
C) A $\gt$ C $\gt$ B
D) B $\gt$ A $\gt$ C
E) A, B, and C have the same area.

Question 29

The time it takes a planet to complete one full orbital revolution is commonly known as its

A) period.
B) frequency.
C) orbital domain.
D) velocity.
E) eccentricity.

Question 30

If a superior planet is observed from Earth to have a synodic period of 1.2 years, what is its sidereal period?

A) 0.54 years
B) 1.8 years
C) 2.3 years
D) 4.0 years
E) 6.0 years

Question 31

Kepler's second law says that if a planet is in an elliptical orbit around a star, then the planet moves fastest when it is

A) farthest from the star.
B) closest to the star.
C) exceeding the escape velocity.
D) experiencing zero acceleration.
E) located at one of the foci.

Question 32

Which of the following is true about a comet that is on an elliptical orbit around the Sun?

A) The comet's speed is greatest when it is farthest from the Sun.
B) The comet's speed is greatest when it is nearest the Sun.
C) This comet's speed is zero.
D) The comet's speed is constant because its mass and the Sun's mass stay approximately the same.
E) The eccentricity is very low.

Question 33

The average distance between a planet and the Sun is given by the ________ of its elliptical orbit.

A) radius
B) semiminor axis
C) eccentricity
D) semimajor axis
E) distance between the foci

Question 34

Which equation represents the relationship of the planet's period to its semimajor axis in data shown in the figure below?

A) P $\infty$ A
B) P² $\infty$ A²
C) P³ $\infty$ A²
D) P² $\infty$ A³
E) P $\infty$ A³

Question 35

If the synodic period of Venus is observed from Earth to be 1.6 years, Venus's sidereal period is ________ years.

A) 1.9
B) 0.45
C) 0.28
D) 1.6
E) 0.62

Question 36

In the figure below, a planet orbits the Sun.During which of the three sections (A, B, or C) will the planet have the lowest average velocity?

A) A
B) B
C) C
D) The average velocity is the same for sections A, B, and C.
E) The information given is insufficient to answer this question.

Question 37

Kepler's model for the solar system has planets traveling on

A) noncircular elliptical orbits.
B) spiral orbits.
C) perfectly circular orbits.
D) epicycles.
E) straight lines through curved space.

Question 38

A circular orbit has an eccentricity of ________ and a very elliptical orbit has an eccentricity of ________.

A) 1; 0
B) 1; 1
C) 0; infinity
D) 0; 1
E) infinity; 0

Question 39

If the Sun is located at one focus of Earth's elliptical orbit, what is at the other focus?

A) Earth
B) the Moon
C) another planet
D) nothing
E) Jupiter

Question 40

If the sidereal period of Jupiter is 11.9 years, what is Jupiter's synodic period as observed from Earth?

A) 2.3 years
B) 0.84 years
C) 0.92 years
D) 1.09 years
E) 1.5 years

Question 41

Galileo observed what the geocentric astronomers viewed as imperfections.These observations helped Galileo to show that the heliocentric model was the more accurate model.Which was not an observation of Galileo's?

A) The Moon had craters.
B) sunspots
C) the moons of Jupiter
D) Venus's phases
E) the moons of Saturn

Question 42

An empirical science is one that is based on

A) assumptions.
B) calculus.
C) computer models.
D) observed data.
E) hypotheses.

Question 43

If you traveled at a velocity of 60 mph for a five-hour trip, how far did you travel?

A) 300 miles
B) 120 miles
C) 12 miles
D) 0.4 miles
E) 240 mph

Question 44

A comet orbits the Sun with a semimajor axis of 90 AU.Using Kepler's third law, the comet's orbital period is approximately

A) 850 years.
B) 630 years.
C) 410 years.
D) 180 years.
E) 90 years.

Question 45

The natural tendency of an object to resist changes in motion is called

A) inertia.
B) weight.
C) acceleration.
D) mass.
E) velocity.

Question 46

Which object, masses listed, will experience the greatest acceleration if the same force is applied to all of them?

A) 1 kg
B) 2 kg
C) 10 kg
D) 20 kg
E) 50 kg

Question 47

Kepler's third law says that a comet with a period of 160 years will have a semimajor axis of

A) 30 AU.
B) 50 AU.
C) 90 AU.
D) 140 AU.
E) 210 AU.

Question 48

The dwarf planet named Eris orbits the Sun with a semimajor axis of 68 AU.Using Kepler's third law, Eris's orbital period is

A) 26 years.
B) 130 years.
C) 72 years.
D) 240 years.
E) 560 years.

Question 49

Which object, masses listed, will have the largest inertia?

A) 1 kg
B) 2 kg
C) 10 kg
D) 20 kg
E) 50 kg

Question 50

Galileo's telescopic observations of the ________ led him to conclude that the heliocentric model of the Solar System was correct.

A) motion of Jupiter and Saturn
B) motion of Venus
C) moons of Jupiter and phases of Venus
D) phases of the Moon
E) epicycles of Mars

Question 51

If Neptune has a semimajor axis of 19 AU, its orbital period is

A) 45 years.
B) 83 years.
C) 130 years.
D) 220 years.
E) 380 years.

Question 52

According to Kepler's laws, a comet with a highly eccentric orbit will

A) spend most of its time near the Sun.
B) spend most of its time far from the Sun.
C) always be the same distance from the Sun.
D) spend the same amount of time everywhere.
E) not travel on an ellipse.

Question 53

If Jupiter has an orbital period of 12 years, what value is closest to its average distance from the Sun?

A) 2 AU
B) 25 AU
C) 10 AU
D) 5 AU
E) 144 AU

Question 54

If you travel at a velocity of 30 miles per hour (mph) during a 15-mile trip from home to school, how long does the trip take?

A) 2 hours
B) 0.2 hours
C) 0.5 hours
D) 5 hours
E) 750 hours

Question 55

If Mercury has an orbital period of about 88 days, what is its average distance from the Sun?

A) 0.2 AU
B) 0.01 AU
C) 0.05 AU
D) 0.4 AU
E) 0.7 AU

Question 56

As a car drives around a corner at constant speed, the car is

A) not accelerating.
B) accelerating because speed is decreasing.
C) accelerating because speed is increasing.
D) accelerating because the direction is changing.
E) accelerating because the applied force is zero.

Question 57

An inertial frame of reference is

A) an object's mass.
B) any moving frame of reference.
C) any frame of reference moving in a straight line at a constant velocity.
D) any rotating frame of reference.
E) any object with a measurable inertia.

Question 58

Newton's first law states that objects in motion

A) eventually come to rest.
B) experience an unbalanced force.
C) experience a nonzero acceleration.
D) stay in motion unless acted upon by an unbalanced force.
E) must be subject to zero friction.

Question 59

Suppose an asteroid had an orbit with a semimajor axis of 4 AU.How long would it take for it to orbit once around the Sun?

A) 76 years
B) 45 years
C) 8 years
D) 16 years
E) 2 years

Question 60

The major component of a physical law that is missing from an empirical law is

A) a theoretical framework.
B) physical data.
C) sound logical deduction.
D) peer review.
E) nothing; they are conceptually identical.

Question 61

If a 100-kg astronaut pushes on a 5,000-kg satellite and the satellite experiences an acceleration of 0.1 m/s², what is the acceleration experienced by the astronaut in the opposite direction?

A) 5 m/s²
B) 10 m/s²
C) 50 m/s²
D) 0.1 m/s²
E) 1,000 m/s²

Question 62

Based on the figure below, explain why an inferior planet is most likely to be seen when it is at one of its greatest elongations.

Question 63

What does the term conjunction mean in planetary orbits?

Question 64

If Venus is at inferior conjunction, what phase would we observe from Earth?

Question 65

Based on the figure below, explain why an inferior planet would not be able to be seen at all from Earth when it is in conjunction.

Question 66

Cars can accelerate forward because

A) car exhaust pushes backwards against the air.
B) car tires push backwards against the road.
C) they are designed to violate Newton's third law of motion.
D) they take advantage of laws of physics discovered later than Newton's laws.
E) car exhaust has zero mass.

Question 67

How was retrograde motion explained in the geocentric system?

Question 68

Who introduced epicycles into the geocentric system? Why?

Question 69

A 100-kg astronaut throws a 1-kg wrench with a force of 1 N.What is the acceleration of the wrench after the wrench leaves the astronaut's hand?

A) More information is needed.
B) 1 m/s²
C) zero
D) 0.01 m/s²
E) 100 m/s

Question 70

If you start from rest and accelerate at 10 mph/s, how long would it take you to reach 60 mph?

A) 1 second
B) 6 seconds
C) 600 seconds
D) 0.6 seconds
E) 200 seconds

Question 71

Based on the figure below, explain why, when a superior planet is in opposition, it will be visible from Earth all night long.

Question 72

Which orbit in the figure below would you expect to result in the least extreme temperature changes for a planet with that orbit?

A) orbit a
B) orbit b
C) orbit c
D) orbit d
E) The shape of a planet's orbit should not affect its temperature.

Question 73

Explain how the Occam's razor argument influenced whether people believed in the heliocentric or the geocentric model of the Solar System.

Question 74

What is your acceleration if you go from 0 to 60 mph in 4 seconds?

A) 60 mph/s
B) 30 mph/s
C) 15 mph/s
D) 8.5 mph/s
E) 240 mph/s

Question 75

Explain what retrograde motion is, and what causes this phenomenon.A drawing is recommended.

Question 76

Based on the figure below, explain why a superior planet, when it is at conjunction, will not be seen at all from Earth during the night.

Question 77

If you apply a force of 10 N to a grocery cart and get an acceleration of 0.5 m/s², then the mass of the grocery cart is

A) 5 kg.
B) 0.05 kg.
C) 20 kg.
D) 50 kg.
E) 0.20 kg.

Question 78

If you start from rest and accelerate at 15 mph/s for 5 seconds, how fast will you be traveling at the end?

A) 75 mph
B) 45 mph
C) 3 mph
D) 12 mph
E) 20 mph

Question 79

You apply a force of 10 N to a grocery cart in order to get an acceleration of 0.5 m/s².If you apply a force of 20 N to the same grocery cart, its acceleration will be

A) 10 m/s².
B) 1 m/s².
C) 0.5 m/s².
D) 0.25m/s².
E) 20 m/s².

Question 80

When an inferior planet has reached its largest angular separation from the Sun on the sky, what is this called?