Question 1

If a person sent a radio message toward the star nearest to the Sun, and intelligent beings from a planet near the star sent back a reply immediately on receipt of the message, how long after the transmission would this person have to wait for a reply?

Accepted Answer

A)   8.4 years
B)   1 light-year
C)   1 year
D)   20,000 years

Question 2

Consider the synodic period for Jupiter. Which planet (or planets)  will be in the same place in its orbit at the beginning and at the end of one synodic period of Jupiter?

Accepted Answer

A)   neither Jupiter nor Earth
B)   Earth but not Jupiter
C)   Jupiter but not Earth
D)   both Jupiter and Earth

Question 3

The direction of retrograde motion for a planet as seen by an observer on Earth is

Accepted Answer

A)   west to east relative to the background stars.
B)   east to west relative to the background stars.
C)   east to west relative to objects on the person's horizon.
D)   west to east relative to objects on the person's horizon.

Question 4

The semimajor axis of an ellipse is

Accepted Answer

A)   the distance from the center of the ellipse to one end, along the largest diameter of the ellipse.
B)   the distance from the center to one side of the ellipse, along the shortest diameter of the ellipse.
C)   the distance from one focus to any point on the circumference of the ellipse.
D)   half the distance between the foci of the ellipse.

Question 5

The planets that were known before the telescope was invented were

Accepted Answer

A)   Mercury, Venus, Mars, Jupiter, and Neptune.
B)   Saturn, Venus, Mars, Mercury, and Jupiter.
C)   Jupiter, Mercury, Mars, Uranus, and Venus.
D)   Venus, Jupiter, Saturn, Mars, and Pluto.

Question 6

Tycho Brahe

Accepted Answer

A)   developed a reflecting telescope, which used a curved mirror to focus the light.
B)   developed the first detailed heliocentric model for the solar system, which replaced the geocentric model of Ptolemy.
C)   improved the refracting telescope, which allowed him to extend Galileo's observations of the sky.
D)   made accurate measurements of planetary positions, which Kepler later used to find the shapes of planetary orbits.

Question 7

In science, if new and reliable observations disagree with a particular theory, then the

Accepted Answer

A)   observations must be discarded.
B)   theory must be modified.
C)   the observations and the theory should both be retained.
D)   theory must be discarded.

Question 8

The acceleration of a body is defined as its rate of change of

Accepted Answer

A)   weight.
B)   velocity.
C)   position.
D)   mass.

Question 9

Retrograde motion of a planet refers to which motion, when viewed from Earth?

Accepted Answer

A)   setting of the planet in the west to any observer, caused by Earth rotation
B)   eastward apparent motion with respect to the stars
C)   southward motion of the planet as it moves away from the northern sky
D)   westward apparent motion with respect to the stars

Question 10

Which of these is a critical component of the scientific method?

Accepted Answer

A)   belief that a theory accepted by leading scientists is correct
B)   rejection of new scientific results when they disagree with the presently accepted theory
C)   automatic rejection of a theory when new results disagree with its predictions
D)   testing of predictions from a scientific theory or theoretical model

Question 11

An unbalanced force acting on an object will always cause it to change its

Accepted Answer

A)   direction of travel.
B)   speed or direction of travel or both.
C)   direction of acceleration.
D)   speed.

Question 12

When Jupiter is at opposition, it will rise at

Accepted Answer

A)   sunrise.
B)   noon.
C)   sunset.
D)   midnight.

Question 13

The strength of gravity on Mars is about 40% of that on Earth. If an astronaut's mass on Earth is 60 kg, what would their mass be on Mars?

Accepted Answer

A)   150 kg
B)   zero
C)   24 kg
D)   60 kg

Question 14

In any one day, the line joining a planet to the Sun will sweep through some particular angle as seen from the Sun. Where is the planet when this angle has its smallest value?

Accepted Answer

A)   at aphelion
B)   at perihelion
C)   at greatest elongation
D)   at inferior conjunction

Question 15

Retrograde motion was important in the development of our understanding of the solar system because

Accepted Answer

A)   it was not discovered until 1920.
B)   it cannot be described with the geocentric model.
C)   its description in terms of the heliocentric model is a great simplification in comparison to its description in terms of the geocentric model.
D)   it happens only about once per century.

Question 16

At what point in a planetary orbit is the planet's speed the slowest?

Accepted Answer

A)   approaching the closest distance to the Sun
B)   at aphelion
C)   at perihelion
D)   at the focus of its orbit

Question 17

Suppose that a planet of 10 times the mass of Earth were orbiting the Sun at the same distance as Earth (1 au) . The gravitational force on this planet due to the Sun would be

Accepted Answer

A)   10 times the gravitational force the Sun exerts on Earth.
B)   100 times the gravitational force the Sun exerts on Earth.
C)   1/100 of the gravitational force the Sun exerts on Earth.
D)   1/10 of the gravitational force the Sun exerts on Earth.

Question 18

If the mass of the Sun were doubled and Jupiter remained at its present distance, the gravitational force the Sun exerted on Jupiter would

Accepted Answer

A)   be 16 times its present value.
B)   stay the same.
C)   be 4 times its present value.
D)   be twice its present value.

Question 19

The planet Venus can never reach which planetary configuration when viewed from Earth?

Accepted Answer

A)   opposition
B)   superior conjunction
C)   inferior conjunction
D)   greatest elongation

Question 20

The orbits of asteroids in the asteroid belt have typical semimajor axes of 2.8 au. According to Kepler's law, the approximate sidereal period of these asteroids is

Accepted Answer

A)   2.8 years.
B)   46.8 years.
C)   1.99 years.
D)   4.68 years.

Exam 2: Gravitation and the Motion of the Planets

Suppose that a planet of 10 times the mass of Earth were orbiting the Sun at the same distance as Earth (1 au) . The gravitational force on this planet due to the Sun would be

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The planet Venus can never reach which planetary configuration when viewed from Earth?

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When Jupiter is at opposition, it will rise at

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The strength of gravity on Mars is about 40% of that on Earth. If an astronaut's mass on Earth is 60 kg, what would their mass be on Mars?

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The semimajor axis of an ellipse is

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Consider the synodic period for Jupiter. Which planet (or planets) will be in the same place in its orbit at the beginning and at the end of one synodic period of Jupiter?

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Tycho Brahe

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An unbalanced force acting on an object will always cause it to change its

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Which of these is a critical component of the scientific method?

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The orbits of asteroids in the asteroid belt have typical semimajor axes of 2.8 au. According to Kepler's law, the approximate sidereal period of these asteroids is

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In science, if new and reliable observations disagree with a particular theory, then the

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The planets that were known before the telescope was invented were

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In any one day, the line joining a planet to the Sun will sweep through some particular angle as seen from the Sun. Where is the planet when this angle has its smallest value?

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If the mass of the Sun were doubled and Jupiter remained at its present distance, the gravitational force the Sun exerted on Jupiter would

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Retrograde motion was important in the development of our understanding of the solar system because

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The direction of retrograde motion for a planet as seen by an observer on Earth is

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Retrograde motion of a planet refers to which motion, when viewed from Earth?

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The acceleration of a body is defined as its rate of change of

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At what point in a planetary orbit is the planet's speed the slowest?

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If a person sent a radio message toward the star nearest to the Sun, and intelligent beings from a planet near the star sent back a reply immediately on receipt of the message, how long after the transmission would this person have to wait for a reply?

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