Question 1

The force that pulls an upward going ball back to Earth and keeps the Moon in its orbit is called _______.

Accepted Answer

A)  inertia 
B)  gravity 
C)  pressure 
D)  escape speed 
A)  inertia 
B)  gravity 
C)  pressure 
D)  escape speed

Question 2

Newton's modification of Kepler's Third law allows astronomers to determine the _____ of celestial objects.

Accepted Answer

A)  mass 
B)  period 
C)  distance 
D)  acceleration 
A)  mass 
B)  period 
C)  distance 
D)  acceleration

Question 3

A delivery truck and a car collide.Which vehicle experiences the greater force?

Accepted Answer

A)  the truck 
B)  the car 
C)  Both the car and the truck experience the same force. 
D)  We need to know the speed of the truck and the car to find the answer. 
E)  We need to know the mass of the truck and the car to find the answer. 
A)  the truck 
B)  the car 
C)  Both the car and the truck experience the same force. 
D)  We need to know the speed of the truck and the car to find the answer. 
E)  We need to know the mass of the truck and the car to find the answer.

Question 4

If it were possible to move Earth so that its new orbit was twice as large as it is now, then the length of a year (in terms of the number of days) would also double.

Accepted Answer

A) True 
 B)False

Question 5

What does surface gravity measure?

Accepted Answer

A)  the tendency of a planet's surface to collapse under gravity 
B)  how fast an object needs to go to escape a planet's gravity 
C)  the attraction between the surfaces of two massive objects 
D)  the gravitational acceleration at a planet's or star's surface 
A)  the tendency of a planet's surface to collapse under gravity 
B)  how fast an object needs to go to escape a planet's gravity 
C)  the attraction between the surfaces of two massive objects 
D)  the gravitational acceleration at a planet's or star's surface

Question 6

Mars completes one orbit around the Sun in approximately two Earth years. Mars orbits at an average distance to the Sun of about 1.5 AU, and Mars' mass is about 1/10 of Earth's mass. Therefore Mars' orbital speed is _____ the orbital speed of Earth.

Accepted Answer

A)  about 0.8 times 
B)  1.5 times larger than 
C)  about 1/10 of 
D)  about 3 times 
A)  about 0.8 times 
B)  1.5 times larger than 
C)  about 1/10 of 
D)  about 3 times

Question 7

The recoil experienced when firing a shotgun is a consequence of _____ law.

Accepted Answer

A)  Newton's First 
B)  Kepler's Third 
C)  Newton's Third 
D)  Kepler's First 
A)  Newton's First 
B)  Kepler's Third 
C)  Newton's Third 
D)  Kepler's First

Question 8

If a newly discovered planet has four times the mass of Earth, but it still has the same surface gravity as Earth, how big must this new planet be?

Accepted Answer

A)  four times as large as Earth 
B)  twice as large as Earth 
C)  the same size as Earth 
D)  half the size of Earth 
E)  one fourth of the size of Earth 
A)  four times as large as Earth 
B)  twice as large as Earth 
C)  the same size as Earth 
D)  half the size of Earth 
E)  one fourth of the size of Earth

Question 9

A delivery truck and a car collide.Which vehicle experiences the greater acceleration?

Accepted Answer

A)  the truck 
B)  the car 
C)  Both the car and the truck experience the same acceleration. 
D)  We need to know the speed of the truck and the car to find the answer. 
E)  We need to know the mass of the truck and the car to find the answer. 
A)  the truck 
B)  the car 
C)  Both the car and the truck experience the same acceleration. 
D)  We need to know the speed of the truck and the car to find the answer. 
E)  We need to know the mass of the truck and the car to find the answer.

Question 10

A rocket in space fires its engines continuously until it runs out of fuel. Describe the motion of the rocket.

Accepted Answer

A)  The rocket's speed increases until its engines stop firing, and then coasts in a straight line. 
B)  The rocket's speed is a constant value until the engines stop firing, and then coasts to a stop. 
C)  The rocket's speed increases until its engines stop firing, and then coasts to a stop. 
D)  The rocket's speed does not change, and it continues to move in a straight line. 
E)  The rocket does not move, as the engines have nothing to push against. 
A)  The rocket's speed increases until its engines stop firing, and then coasts in a straight line. 
B)  The rocket's speed is a constant value until the engines stop firing, and then coasts to a stop. 
C)  The rocket's speed increases until its engines stop firing, and then coasts to a stop. 
D)  The rocket's speed does not change, and it continues to move in a straight line. 
E)  The rocket does not move, as the engines have nothing to push against.

Question 11

At which place on the Earth will you weigh less?

Accepted Answer

A)  at the equator 
B)  at the North Pole 
C)  at the South Pole 
D)  you weigh the same at all of these places 
A)  at the equator 
B)  at the North Pole 
C)  at the South Pole 
D)  you weigh the same at all of these places

Question 12

Why does something weigh less on the Moon than on Earth?

Accepted Answer

A)  The farther something is from Earth, the lower its weight. 
B)  The Moon's lower mass creates a lower force of gravity at its surface. 
C)  The object's weight is the same on the Moon as it is on Earth. 
D)  Earth's gravity pulls in the opposite direction as the Moon's, so the net force is reduced. 
E)  The Moon has no atmosphere to apply a downward force on surface objects. 
A)  The farther something is from Earth, the lower its weight. 
B)  The Moon's lower mass creates a lower force of gravity at its surface. 
C)  The object's weight is the same on the Moon as it is on Earth. 
D)  Earth's gravity pulls in the opposite direction as the Moon's, so the net force is reduced. 
E)  The Moon has no atmosphere to apply a downward force on surface objects.

Question 13

Consider an apple falling from a tree. Which of the following apply to this situation?

Accepted Answer

A)  The apple is attracting Earth. 
B)  Earth is attracting the apple. 
C)  Earth is attracting the apple; the apple is not attracting Earth. 
D)  The apple is attracting Earth and Earth is attracting the apple. 
A)  The apple is attracting Earth. 
B)  Earth is attracting the apple. 
C)  Earth is attracting the apple; the apple is not attracting Earth. 
D)  The apple is attracting Earth and Earth is attracting the apple.

Question 14

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the speed of the spacecraft near the beginning of its journey with its speed as it flies past Pluto.

Accepted Answer

A)  The spacecraft's speed at Pluto is the same as its speed near Earth. 
B)  The spacecraft's speed at Pluto is slower than its speed near Earth. 
C)  The spacecraft's speed at Pluto is faster than its speed near Earth. 
D)  The relative speed cannot be determined with the information given. 
A)  The spacecraft's speed at Pluto is the same as its speed near Earth. 
B)  The spacecraft's speed at Pluto is slower than its speed near Earth. 
C)  The spacecraft's speed at Pluto is faster than its speed near Earth. 
D)  The relative speed cannot be determined with the information given.

Question 15

The acceleration of gravity on Earth's surface is 9.8 m/s2. What is the acceleration of gravity at a height of 6,400 km above Earth's surface? (Hint: recall the 1/r2 dependence and note that Earth's radius is 6,400 km.)

Accepted Answer

A)  4.9 m/s 2 
B)  2.45 m/s 2 
C)  19.6 m/s 2 
D)  9.8 m/s 2 
A)  4.9 m/s 2 
B)  2.45 m/s 2 
C)  19.6 m/s 2 
D)  9.8 m/s 2

Question 16

A bowling ball exerts a force on the pins when it strikes them, knocking them down.The force of the pins on the ball is ____.

Accepted Answer

A)  less than the force of the ball on the pins 
B)  the same as the force of the ball on the pins 
C)  larger than the force of the ball on the pins 
D)  either less or more, depending on how hard the ball is thrown 
E)  A system of ten bowling pins is too complicated to know the force on the ball 
A)  less than the force of the ball on the pins 
B)  the same as the force of the ball on the pins 
C)  larger than the force of the ball on the pins 
D)  either less or more, depending on how hard the ball is thrown 
E)  A system of ten bowling pins is too complicated to know the force on the ball

Question 17

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the acceleration of the spacecraft near the beginning of its journey with its acceleration as it flies past Pluto.

Accepted Answer

A)  The spacecraft's acceleration at Pluto is the same as its acceleration near Earth. 
B)  The spacecraft's acceleration at Pluto is slower than its acceleration near Earth. 
C)  The spacecraft's acceleration at Pluto is faster than its acceleration near Earth. 
D)  The relative acceleration cannot be determined with the information given. 
A)  The spacecraft's acceleration at Pluto is the same as its acceleration near Earth. 
B)  The spacecraft's acceleration at Pluto is slower than its acceleration near Earth. 
C)  The spacecraft's acceleration at Pluto is faster than its acceleration near Earth. 
D)  The relative acceleration cannot be determined with the information given.

Question 18

If a barbell weighs 10 pounds on the Moon, what would it weigh on Earth?

Accepted Answer

A)  1.67 pounds. Surface gravity on the Moon is 1/6 that on Earth. 
B)  10 pounds. Gravity is the same on Earth and the Moon. 
C)  30 pounds. Surface gravity on Earth is 3 times that on the Moon. 
D)  60 pounds. Surface gravity on Earth is 6 times that on the Moon. 
A)  1.67 pounds. Surface gravity on the Moon is 1/6 that on Earth. 
B)  10 pounds. Gravity is the same on Earth and the Moon. 
C)  30 pounds. Surface gravity on Earth is 3 times that on the Moon. 
D)  60 pounds. Surface gravity on Earth is 6 times that on the Moon.

Question 19

The Moon is gravitationally attracted to Earth. Is Earth gravitationally attracted to the Moon?

Accepted Answer

A)  Yes, but the force of attraction is less. 
B)  Yes, and the force of attraction is the same. 
C)  Yes, but the force of attraction is greater. 
D)  No, the Moon has no gravity. 
A)  Yes, but the force of attraction is less. 
B)  Yes, and the force of attraction is the same. 
C)  Yes, but the force of attraction is greater. 
D)  No, the Moon has no gravity.

Question 20

How can we mathematically express Newton's law of gravity? (In the following, F is the force of Gravity, G is a constant; m and M are the masses or two bodies (such as Earth and the Sun); and r is the distance between the centers of mass of the two bodies.)

Accepted Answer

A)  F = GMm/r 
B)  F = GMm/r2 
C)  F = GMm/r3 
D)  F = Gm2M/r2 
A)  F = GMm/r 
B)  F = GMm/r2 
C)  F = GMm/r3 
D)  F = Gm2M/r2

The force that pulls an upward going ball back to Earth and keeps the Moon in its orbit is called _______.

Newton's modification of Kepler's Third law allows astronomers to determine the _____ of celestial objects.

A delivery truck and a car collide.Which vehicle experiences the greater force?

If it were possible to move Earth so that its new orbit was twice as large as it is now, then the length of a year (in terms of the number of days) would also double.

What does surface gravity measure?

Mars completes one orbit around the Sun in approximately two Earth years. Mars orbits at an average distance to the Sun of about 1.5 AU, and Mars' mass is about 1/10 of Earth's mass. Therefore Mars' orbital speed is _____ the orbital speed of Earth.

The recoil experienced when firing a shotgun is a consequence of _____ law.

If a newly discovered planet has four times the mass of Earth, but it still has the same surface gravity as Earth, how big must this new planet be?

A delivery truck and a car collide.Which vehicle experiences the greater acceleration?

A rocket in space fires its engines continuously until it runs out of fuel. Describe the motion of the rocket.

At which place on the Earth will you weigh less?

Why does something weigh less on the Moon than on Earth?

Consider an apple falling from a tree. Which of the following apply to this situation?

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the speed of the spacecraft near the beginning of its journey with its speed as it flies past Pluto.

The acceleration of gravity on Earth's surface is 9.8 m/s². What is the acceleration of gravity at a height of 6,400 km above Earth's surface? (Hint: recall the 1/r² dependence and note that Earth's radius is 6,400 km.)

A bowling ball exerts a force on the pins when it strikes them, knocking them down.The force of the pins on the ball is ____.

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the acceleration of the spacecraft near the beginning of its journey with its acceleration as it flies past Pluto.

If a barbell weighs 10 pounds on the Moon, what would it weigh on Earth?

The Moon is gravitationally attracted to Earth. Is Earth gravitationally attracted to the Moon?

How can we mathematically express Newton's law of gravity? (In the following, F is the force of Gravity, G is a constant; m and M are the masses or two bodies (such as Earth and the Sun); and r is the distance between the centers of mass of the two bodies.)

The Cycles of the Sky

The Rise of Astronomy

Light and Atoms

Telescopes

Earth

The Moon

Survey of Solar Systems

The Terrestrial Planets

The Outer Planets

Small Bodies Orbiting the Sun

The Sun, Our Star

Measuring the Properties of Stars

Stellar Evolution

Stellar Remnants: White Dwarfs, Neutron Stars, and Black Holes

The Milky Way Galaxy

Galaxies

Cosmology

Filters

Exam 3: Gravity and Motion

The force that pulls an upward going ball back to Earth and keeps the Moon in its orbit is called _______.

Newton's modification of Kepler's Third law allows astronomers to determine the _____ of celestial objects.

A delivery truck and a car collide.Which vehicle experiences the greater force?

If it were possible to move Earth so that its new orbit was twice as large as it is now, then the length of a year (in terms of the number of days) would also double.

What does surface gravity measure?

Mars completes one orbit around the Sun in approximately two Earth years. Mars orbits at an average distance to the Sun of about 1.5 AU, and Mars' mass is about 1/10 of Earth's mass. Therefore Mars' orbital speed is _____ the orbital speed of Earth.

The recoil experienced when firing a shotgun is a consequence of _____ law.

If a newly discovered planet has four times the mass of Earth, but it still has the same surface gravity as Earth, how big must this new planet be?

A delivery truck and a car collide.Which vehicle experiences the greater acceleration?

A rocket in space fires its engines continuously until it runs out of fuel. Describe the motion of the rocket.

At which place on the Earth will you weigh less?

Why does something weigh less on the Moon than on Earth?

Consider an apple falling from a tree. Which of the following apply to this situation?

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the speed of the spacecraft near the beginning of its journey with its speed as it flies past Pluto.

The acceleration of gravity on Earth's surface is 9.8 m/s2. What is the acceleration of gravity at a height of 6,400 km above Earth's surface? (Hint: recall the 1/r2 dependence and note that Earth's radius is 6,400 km.)

A bowling ball exerts a force on the pins when it strikes them, knocking them down.The force of the pins on the ball is ____.

An ion engine provides a small but constant force on a spacecraft as it moves from Earth to Pluto. Compare the acceleration of the spacecraft near the beginning of its journey with its acceleration as it flies past Pluto.

If a barbell weighs 10 pounds on the Moon, what would it weigh on Earth?

The Moon is gravitationally attracted to Earth. Is Earth gravitationally attracted to the Moon?

How can we mathematically express Newton's law of gravity? (In the following, F is the force of Gravity, G is a constant; m and M are the masses or two bodies (such as Earth and the Sun); and r is the distance between the centers of mass of the two bodies.)

The Cycles of the Sky

The Rise of Astronomy

Light and Atoms

Telescopes

Earth

The Moon

Survey of Solar Systems

The Terrestrial Planets

The Outer Planets

Small Bodies Orbiting the Sun

The Sun, Our Star

Measuring the Properties of Stars

Stellar Evolution

Stellar Remnants: White Dwarfs, Neutron Stars, and Black Holes

The Milky Way Galaxy

Galaxies

Cosmology

Filters

The acceleration of gravity on Earth's surface is 9.8 m/s². What is the acceleration of gravity at a height of 6,400 km above Earth's surface? (Hint: recall the 1/r² dependence and note that Earth's radius is 6,400 km.)