Question 1

How far from Earth on a line between the Earth (5.97 * 1024 kg)and the Moon (7.36 * 1022 kg)is the gravitational force on a spacecraft due to Earth and Moon equal to zero? Report as a fraction of the Earth-Moon distance.

Accepted Answer

A) 99% of Earth-Moon distance 
B) 90% of Earth-Moon distance 
C) 81% of Earth-Moon distance 
D) 11% of Earth-Moon distance 
E) 1.2% of Earth-Moon distance

Question 2

Which is larger in magnitude,the force of gravity of the Earth on the Moon,or the force of gravity of the Moon on the Earth?

Accepted Answer

A) The Earth exerts a larger force on the Moon. 
B) The Moon exerts a larger force on the Earth. 
C) The two forces are equal in magnitude.

Question 3

A projectile is shot from the surface of Earth by means of a very powerful cannon.If the projectile reaches a height of 100.0 km above Earth's surface,what was the speed of the projectile when it left the cannon?

Accepted Answer

A) 1036 m/s 
B) 1123 m/s 
C) 1265 m/s 
D) 1392 m/s 
E) 1409 m/s

Question 4

What is the magnitude of free fall acceleration at an altitude h = R where R is the radius of the Earth?

Accepted Answer

A) 9.81 m/s2 
B) 4.90 m/s2 
C) 3.27 m/s2 
D) 2.45 m/s2 
E) 1.09 m/s2

Question 5

Two objects aren't in contact,but they affect each other via the gravitational force,and there aren't any other forces acting on either object.Which statement is always true?

Accepted Answer

A) The magnitude of the gravitational force is the same on both objects. 
B) The direction of the gravitational force is the same on both objects. 
C) The magnitude of the acceleration is the same for both objects. 
D) The direction of the acceleration is the same for both objects.

Question 6

A space station is placed between a planet and its single moon at a position where the net force on the space station is zero.If the planet has a mass 1000 times larger than its moon,how far from the planet is the space station?

Accepted Answer

A) 50.0% of the way to the moon 
B) 68.4% of the way to the moon 
C) 94.4% of the way to the moon 
D) 96.9% of the way to the moon 
E) 99.9% of the way to the moon

Question 7

The period of a particular satellite is exactly 24 hours.How high above the surface of the Earth is it orbiting? The Earth's mass is 5.97 * 1024 kg,and the Earth's radius is 6378 km.

Accepted Answer

A) 42.2 * 103 km 
B) 35.8 * 103 km 
C) 61.8 * 103 km 
D) 55.4 * 103 km 
E) The mass of the satellite is needed.

Question 8

A spaceship is fired from the Earth's surface with a speed of v.The radius of the Earth is R,the mass of the Earth is M,and the universal gravitational constant is

Accepted Answer

A)   
B)   
C)   
D)   
E) It is impossible to determine.

Question 9

A satellite is in a stable orbit at an elevation above the surface of the Earth equal to the radius of the Earth.An asteroid collides with the satellite.Both objects stop moving and fall straight down.How fast are the satellite and asteroid moving when they hit the surface of the Earth? In the answers,r = the radius of the Earth and m = the mass of the Earth.Ignore air resistance.

Accepted Answer

A)   
B)   
C)   
D) None are correct.

Question 10

Before the discovery of Pluto's moon,Charon,Pluto's mass was estimated to be around 6 * 1022 kg.If Charon orbits Pluto with a period of 153 hours at a distance of 1.75 * 107m estimate the mass of Pluto.

Accepted Answer

A) 3.15 * 1021 kg 
B) 3.18 * 1022 kg 
C) 1.04 * 1022 kg 
D) 1.14 * 1022 kg 
E) 6.31 * 1022 kg

Question 11

You are standing on the surface of a small spherical moon whose radius is 6.30 * 104 m and mass of 8.00 * 1018 kg.An astronaut throws a rock of mass 5.00 kg straight upward with a speed 20.0 m/s.(This Moon is too small to have an atmosphere.)What maximum height above the surface of the Moon will the rock reach?

Accepted Answer

A) 0.237 km 
B) 0.563 km 
C) 1.00 km 
D) 1.49 km 
E) 1.52 km

Question 12

A satellite orbits around the Earth.Which statement below is true? K = kinetic energy of the satellite
U = gravitational potential energy of the satellite

Accepted Answer

A) K > 0,U > 0 
B) K > 0,U  0 
D) K  0,U = 0

Question 13

A planet with a mass of 2.7 *1022 kg is in a circular orbit around a star with a mass of 5.3 * 1032 kg.If the planet has an orbital radius of 4.8 * 109 m,what is its orbital period?

Accepted Answer

A) 0.29 hours 
B) 0.43 hours 
C) 3.1 hours 
D) 25 years 
E) 49 years

Exam 12: Gravitation

How far from Earth on a line between the Earth (5.97 * 10²⁴ kg) and the Moon (7.36 * 10²² kg) is the gravitational force on a spacecraft due to Earth and Moon equal to zero? Report as a fraction of the Earth-Moon distance.

Which is larger in magnitude,the force of gravity of the Earth on the Moon,or the force of gravity of the Moon on the Earth?

A projectile is shot from the surface of Earth by means of a very powerful cannon.If the projectile reaches a height of 100.0 km above Earth's surface,what was the speed of the projectile when it left the cannon?

What is the magnitude of free fall acceleration at an altitude h = R where R is the radius of the Earth?

Two objects aren't in contact,but they affect each other via the gravitational force,and there aren't any other forces acting on either object.Which statement is always true?

A space station is placed between a planet and its single moon at a position where the net force on the space station is zero.If the planet has a mass 1000 times larger than its moon,how far from the planet is the space station?

The period of a particular satellite is exactly 24 hours.How high above the surface of the Earth is it orbiting? The Earth's mass is 5.97 * 10²⁴ kg,and the Earth's radius is 6378 km.

A spaceship is fired from the Earth's surface with a speed of v.The radius of the Earth is R,the mass of the Earth is M,and the universal gravitational constant is

Before the discovery of Pluto's moon,Charon,Pluto's mass was estimated to be around 6 * 10²² kg.If Charon orbits Pluto with a period of 153 hours at a distance of 1.75 * 10⁷m estimate the mass of Pluto.

A satellite orbits around the Earth.Which statement below is true? K = kinetic energy of the satellite U = gravitational potential energy of the satellite

A planet with a mass of 2.7 10²² kg is in a circular orbit around a star with a mass of 5.3 10³² kg.If the planet has an orbital radius of 4.8 * 10⁹ m,what is its orbital period?

Exam 12: Gravitation

How far from Earth on a line between the Earth (5.97 * 1024 kg) and the Moon (7.36 * 1022 kg) is the gravitational force on a spacecraft due to Earth and Moon equal to zero? Report as a fraction of the Earth-Moon distance.

Which is larger in magnitude,the force of gravity of the Earth on the Moon,or the force of gravity of the Moon on the Earth?

A projectile is shot from the surface of Earth by means of a very powerful cannon.If the projectile reaches a height of 100.0 km above Earth's surface,what was the speed of the projectile when it left the cannon?

What is the magnitude of free fall acceleration at an altitude h = R where R is the radius of the Earth?

Two objects aren't in contact,but they affect each other via the gravitational force,and there aren't any other forces acting on either object.Which statement is always true?

A space station is placed between a planet and its single moon at a position where the net force on the space station is zero.If the planet has a mass 1000 times larger than its moon,how far from the planet is the space station?

The period of a particular satellite is exactly 24 hours.How high above the surface of the Earth is it orbiting? The Earth's mass is 5.97 * 1024 kg,and the Earth's radius is 6378 km.

A spaceship is fired from the Earth's surface with a speed of v.The radius of the Earth is R,the mass of the Earth is M,and the universal gravitational constant is

Before the discovery of Pluto's moon,Charon,Pluto's mass was estimated to be around 6 * 1022 kg.If Charon orbits Pluto with a period of 153 hours at a distance of 1.75 * 107m estimate the mass of Pluto.

A satellite orbits around the Earth.Which statement below is true? K = kinetic energy of the satellite U = gravitational potential energy of the satellite

A planet with a mass of 2.7 *1022 kg is in a circular orbit around a star with a mass of 5.3 * 1032 kg.If the planet has an orbital radius of 4.8 * 109 m,what is its orbital period?

How far from Earth on a line between the Earth (5.97 * 10²⁴ kg) and the Moon (7.36 * 10²² kg) is the gravitational force on a spacecraft due to Earth and Moon equal to zero? Report as a fraction of the Earth-Moon distance.

The period of a particular satellite is exactly 24 hours.How high above the surface of the Earth is it orbiting? The Earth's mass is 5.97 * 10²⁴ kg,and the Earth's radius is 6378 km.

Before the discovery of Pluto's moon,Charon,Pluto's mass was estimated to be around 6 * 10²² kg.If Charon orbits Pluto with a period of 153 hours at a distance of 1.75 * 10⁷m estimate the mass of Pluto.

A planet with a mass of 2.7 10²² kg is in a circular orbit around a star with a mass of 5.3 10³² kg.If the planet has an orbital radius of 4.8 * 10⁹ m,what is its orbital period?