Question 1

The minimum speed required to launch an object so that it remains the same distance above the ground and just falls around the Earth is called:

Accepted Answer

A)  perigee speed 
B)  circular satellite velocity 
C)  Newtonian orbit velocity 
D)  the Keplerian speed 
E)  the speed of sound (or Mach 1) 
A)  perigee speed 
B)  circular satellite velocity 
C)  Newtonian orbit velocity 
D)  the Keplerian speed 
E)  the speed of sound (or Mach 1) B

Question 2

To figure out what you weigh on the surface of the Moon (how much gravity there pulls you downward), you need to know

Accepted Answer

A)  just the mass of the Moon 
B)  just the distance from the Moon's center to its surface 
C)  just the size of the Moon's orbit around the Earth (its semi-major axis, say) 
D)  which part of its orbit the Moon is in 
E)  two of the above factors
3)4 Orbits in the Solar System 
A)  just the mass of the Moon 
B)  just the distance from the Moon's center to its surface 
C)  just the size of the Moon's orbit around the Earth (its semi-major axis, say) 
D)  which part of its orbit the Moon is in 
E)  two of the above factors
3)4 Orbits in the Solar System C

Question 3

Credit for the discovery of Neptune is shared by two astronomers. They are:

Accepted Answer

A)  Hubble and Humason 
B)  Kepler and Newton 
C)  Adams and Leverrier 
D)  Doppler and Wien 
E)  Fraknoi and Morrison 
A)  Hubble and Humason 
B)  Kepler and Newton 
C)  Adams and Leverrier 
D)  Doppler and Wien 
E)  Fraknoi and Morrison C

Question 4

To come up with the precise mathematical form of his law of gravity, Newton first had to invent the mathematical techniques that we now call:

Accepted Answer

A)  algebra 
B)  ratio and proportions 
C)  angular momentum 
D)  calculus 
E)  scientific notation 
A)  algebra 
B)  ratio and proportions 
C)  angular momentum 
D)  calculus 
E)  scientific notation

Question 5

The planet Neptune was discovered by means of:

Accepted Answer

A)  careful observations of its motion by one astronomer in England (done over most of his lifetime) 
B)  observations of its motion performed over many years by astronomers all over the globe 
C)  radio observations of its large magnetic field 
D)  mathematical calculations of how it was perturbing the motion of a neighbor planet 
E)  discrepancies in the horoscopes of famous actors and actresses; errors in the horoscopes showed astrologers that there must be another cosmic influence on their love lives 
A)  careful observations of its motion by one astronomer in England (done over most of his lifetime) 
B)  observations of its motion performed over many years by astronomers all over the globe 
C)  radio observations of its large magnetic field 
D)  mathematical calculations of how it was perturbing the motion of a neighbor planet 
E)  discrepancies in the horoscopes of famous actors and actresses; errors in the horoscopes showed astrologers that there must be another cosmic influence on their love lives

Question 6

The first artificial satellite the human race lofted into orbit was called:

Accepted Answer

A)  Pioneer 
B)  Explorer 
C)  Newton 
D)  Sputnik 
E)  Luna 
A)  Pioneer 
B)  Explorer 
C)  Newton 
D)  Sputnik 
E)  Luna

Question 7

According to Kepler's 2nd Law, comets (which have eccentric orbits) should spend a lot more of their time:

Accepted Answer

A)  close to the planets 
B)  close to the Sun 
C)  losing angular momentum 
D)  far from the Sun 
E)  increasing the rate at which they spin 
A)  close to the planets 
B)  close to the Sun 
C)  losing angular momentum 
D)  far from the Sun 
E)  increasing the rate at which they spin

Question 8

Which of the following statements about the force of gravity is FALSE?

Accepted Answer

A)  it is a universal force, which acts everywhere in space 
B)  its strength decreases as the square of the distance 
C)  its strength is inversely proportional to the mass: the more mass, the less gravity 
D)  the force never becomes zero 
E)  it causes the paths of the planets to be ellipses and not straight lines 
A)  it is a universal force, which acts everywhere in space 
B)  its strength decreases as the square of the distance 
C)  its strength is inversely proportional to the mass: the more mass, the less gravity 
D)  the force never becomes zero 
E)  it causes the paths of the planets to be ellipses and not straight lines

Question 9

To leave the gravitational pull of the Earth, and explore other planets, satellites must have at least:

Accepted Answer

A)  circular satellite velocity 
B)  escape velocity 
C)  perigee velocity 
D)  three orbit perturbation 
E)  the permission of one Congressional committee 
A)  circular satellite velocity 
B)  escape velocity 
C)  perigee velocity 
D)  three orbit perturbation 
E)  the permission of one Congressional committee

Question 10

In an ellipse, the ratio of the distance between the foci and the length of the major axis is called:

Accepted Answer

A)  the eccentricity 
B)  the semi-major axis 
C)  perihelion 
D)  the astronomical unit 
E)  Newton's ratio 
A)  the eccentricity 
B)  the semi-major axis 
C)  perihelion 
D)  the astronomical unit 
E)  Newton's ratio

Question 11

A single star in the process of forming starts by spinning slowly (while it is quite large and relatively cool.) As the star collapses under the pull of its own gravity, its size decreases. As a result, its rate of spinning:

Accepted Answer

A)  will increase 
B)  will decrease 
C)  will stay the same 
D)  will either increase or decrease depending on the star's temperature 
E)  this question cannot be answered from the information we are given 
A)  will increase 
B)  will decrease 
C)  will stay the same 
D)  will either increase or decrease depending on the star's temperature 
E)  this question cannot be answered from the information we are given

Question 12

What specific event really made it possible for the three laws of planetary motion to be discovered?

Accepted Answer

A)  a brilliant comet in 1601 blazed across the sky and was seen to cross in front of Venus 
B)  Tycho Brahe died and his assistant was able to get full access to his data 
C)  Galileo's books were published in Danish and became widely available to the public 
D)  an alignment of all the known planets in one part of the sky called everyone's attention to them 
E)  the plague broke out in England and forced Isaac Newton to return home from college 
A)  a brilliant comet in 1601 blazed across the sky and was seen to cross in front of Venus 
B)  Tycho Brahe died and his assistant was able to get full access to his data 
C)  Galileo's books were published in Danish and became widely available to the public 
D)  an alignment of all the known planets in one part of the sky called everyone's attention to them 
E)  the plague broke out in England and forced Isaac Newton to return home from college

Question 13

Small changes in the orbits of planets caused by the gravitational pull of the other planets in the solar system are called:

Accepted Answer

A)  perturbations 
B)  reaction forces 
C)  foci 
D)  perigee pulls 
E)  eccentricities 
A)  perturbations 
B)  reaction forces 
C)  foci 
D)  perigee pulls 
E)  eccentricities

Question 14

The asteroid belt is

Accepted Answer

A)  a region of icy chunks of material beyond the orbit of Pluto 
B)  a zone where rocky chunks orbit between Mars and Jupiter 
C)  a series of orbital zones around the Moon, from which fragments drop down to form craters 
D)  is a region around the Earth from which meteors (shooting stars) are observed to drop 
E)  a new fashion accessory being sold by NASA to raise funds for future missions
3)5 Motions of Satellites and Spacecraft 
A)  a region of icy chunks of material beyond the orbit of Pluto 
B)  a zone where rocky chunks orbit between Mars and Jupiter 
C)  a series of orbital zones around the Moon, from which fragments drop down to form craters 
D)  is a region around the Earth from which meteors (shooting stars) are observed to drop 
E)  a new fashion accessory being sold by NASA to raise funds for future missions
3)5 Motions of Satellites and Spacecraft

Question 15

Newton's reformulation of Kepler's third law allows us to measure the masses of bodies in orbit around each other, if we can measure:

Accepted Answer

A)  the rotation rate of each object 
B)  the distances and periods of revolution 
C)  the eccentricities and semi-major axes 
D)  the force and the reaction force 
E)  the sweetness of those fig-filled cookie bars 
A)  the rotation rate of each object 
B)  the distances and periods of revolution 
C)  the eccentricities and semi-major axes 
D)  the force and the reaction force 
E)  the sweetness of those fig-filled cookie bars

Question 16

After a long night of cramming for a test, your college room-mate hits his head forcefully against the wall of your room in despair. According to Newton's 3rd Law, as he exerts a force against the wall, there must be an equal and opposite force. How does that opposite force show itself in this case?

Accepted Answer

A)  Your room-mate is pulled downward by gravity 
B)  The wall exerts a force on your room-mate's head and he has a headache 
C)  The wall has a huge dent in it 
D)  There is an exception to the Law for solid objects like walls, so there is no opposite force 
E)  The resident assistant assigned to your floor makes a complaint against the two of you
3)3 Newton's Universal Law of Gravitation 
A)  Your room-mate is pulled downward by gravity 
B)  The wall exerts a force on your room-mate's head and he has a headache 
C)  The wall has a huge dent in it 
D)  There is an exception to the Law for solid objects like walls, so there is no opposite force 
E)  The resident assistant assigned to your floor makes a complaint against the two of you
3)3 Newton's Universal Law of Gravitation

Question 17

Why do satellites launched into low-Earth orbits not remain there indefinitely?

Accepted Answer

A)  they do not have enough speed to fall freely around the Earth 
B)  they tend to collide with other spacecraft and spacecraft fragments 
C)  they lose speed due to friction with the upper layers of the Earth's atmosphere 
D)  they run out of fuel, and without fuel, all satellites, no matter what their orbit is, must fall 
E)  this is an unsolved problem, but a NASA committee has been assigned to work on it 
A)  they do not have enough speed to fall freely around the Earth 
B)  they tend to collide with other spacecraft and spacecraft fragments 
C)  they lose speed due to friction with the upper layers of the Earth's atmosphere 
D)  they run out of fuel, and without fuel, all satellites, no matter what their orbit is, must fall 
E)  this is an unsolved problem, but a NASA committee has been assigned to work on it

Question 18

In Newton's Law of Gravity, the force of gravity goes up as the:

Accepted Answer

A)  mass goes down 
B)  distance goes up 
C)  mass goes up 
D)  distance goes down 
E)  more than one of the above 
A)  mass goes down 
B)  distance goes up 
C)  mass goes up 
D)  distance goes down 
E)  more than one of the above

Question 19

The planet in our solar system whose orbit actually brings it inside the orbit of another planet is:

Accepted Answer

A)  Neptune 
B)  Pluto 
C)  Earth 
D)  Mars 
E)  Mercury 
A)  Neptune 
B)  Pluto 
C)  Earth 
D)  Mars 
E)  Mercury

Question 20

The Earth's escape speed (the speed you need to get away forever) is about 25,000 miles per hour. Escape speed depends on the gravity of the object trying to hold the spacecraft from escaping. Based on your understanding of gravity, how will the escape speed from the Moon compare to the escape speed from Earth?

Accepted Answer

A)  The Moon's escape speed will be greater than Earth's 
B)  The Moon's escape speed will be smaller than Earth's 
C)  The Moon's escape speed will be exactly the same as Earth's 
D)  The Moon's escape speed will change depending on whether it's a crescent Moon or a full Moon 
E)  The Moon's escape speed will be balanced by the Earth being so close and it will be zero
3)6 Gravity with More Than Two Bodies 
A)  The Moon's escape speed will be greater than Earth's 
B)  The Moon's escape speed will be smaller than Earth's 
C)  The Moon's escape speed will be exactly the same as Earth's 
D)  The Moon's escape speed will change depending on whether it's a crescent Moon or a full Moon 
E)  The Moon's escape speed will be balanced by the Earth being so close and it will be zero
3)6 Gravity with More Than Two Bodies

Exam 3: Orbits and Gravity

The minimum speed required to launch an object so that it remains the same distance above the ground and just falls around the Earth is called:

To figure out what you weigh on the surface of the Moon (how much gravity there pulls you downward), you need to know

Credit for the discovery of Neptune is shared by two astronomers. They are:

To come up with the precise mathematical form of his law of gravity, Newton first had to invent the mathematical techniques that we now call:

The planet Neptune was discovered by means of:

The first artificial satellite the human race lofted into orbit was called:

According to Kepler's 2nd Law, comets (which have eccentric orbits) should spend a lot more of their time:

Which of the following statements about the force of gravity is FALSE?

To leave the gravitational pull of the Earth, and explore other planets, satellites must have at least:

In an ellipse, the ratio of the distance between the foci and the length of the major axis is called:

A single star in the process of forming starts by spinning slowly (while it is quite large and relatively cool.) As the star collapses under the pull of its own gravity, its size decreases. As a result, its rate of spinning:

What specific event really made it possible for the three laws of planetary motion to be discovered?

Small changes in the orbits of planets caused by the gravitational pull of the other planets in the solar system are called:

The asteroid belt is

Newton's reformulation of Kepler's third law allows us to measure the masses of bodies in orbit around each other, if we can measure:

Why do satellites launched into low-Earth orbits not remain there indefinitely?

In Newton's Law of Gravity, the force of gravity goes up as the:

The planet in our solar system whose orbit actually brings it inside the orbit of another planet is:

Science and the Universe: a Brief Tour

Observing the Sky: the Birth of Astronomy

Earth, Moon, and Sky

Radiation and Spectra

Astronomical Instruments

Other Worlds: an Introduction to the Solar System

Earth As a Planet

Cratered Worlds: the Moon and Mercury

Earthlike Planets: Venus and Mars

The Giant Planets

Rings, Moons, and Pluto

Comets and Asteroids: Debris of the Solar System

Cosmic Samples and the Origin of the Solar System

The Sun: a Garden-Variety Star

The Sun: a Nuclear Powerhouse

Analyzing Starlight

The Stars: a Celestial Census

Celestial Distances

Between the Stars

The Birth of Stars and the Discovery of Planets Outside the Solar System

Stars From Adolescence to Old Age

The Death of Stars

Black Holes and Curved Space-Time

The Milky Way Galaxy

Galaxies

Active Galaxies, Quasars, and Supermassive Black Holes

The Evolution and Distribution of Galaxies

The Big Bang

Life in the Universe

Filters