Question 1

A spaceship is traveling to the Moon.At what point is it beyond the pull of Earth's gravity?

Accepted Answer

A) when it gets above the atmosphere 
B) when it is half-way there 
C) when it is closer to the Moon than it is to Earth 
D) It is never beyond the pull of Earth's gravity. 
A) when it gets above the atmosphere 
B) when it is half-way there 
C) when it is closer to the Moon than it is to Earth 
D) It is never beyond the pull of Earth's gravity. D

Question 2

A spherically symmetric planet has four times the earth's mass and twice its radius.If a jar of peanut butter weighs 12 N on the surface of the Earth,how much would it weigh on the surface of this planet?

Accepted Answer

A) 3.0 N 
B) 6.0 N 
C) 12 N 
D) 24 N 
E) 36 N 
A) 3.0 N 
B) 6.0 N 
C) 12 N 
D) 24 N 
E) 36 N C

Question 3

A satellite of mass M takes time T to orbit a planet.If the satellite had twice as much mass,the time for it to orbit the planet at the same altitude would be

Accepted Answer

A) 4T. 
B) 2T. 
C) T. 
D) T/2. 
E) T/4. 
A) 4T. 
B) 2T. 
C) T. 
D) T/2. 
E) T/4. C

Question 4

The mass of Pluto is 1.31 × 1022 kg and its radius is 1.15 × 106 m.What is the acceleration of a freely-falling object at the surface of Pluto if it has no atmosphere? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 0.661 m/s2 
B) 9.81 m/s2 
C) 1.62 m/s2 
D) 3.72 m/s2 
E) 0.140 m/s2 
A) 0.661 m/s2 
B) 9.81 m/s2 
C) 1.62 m/s2 
D) 3.72 m/s2 
E) 0.140 m/s2

Question 5

In another solar system,a planet has an airless moon Zygo that is 4.0 × 105 m in diameter.Experiments reveal that a freely falling object at the surface of Zygo accelerates at 0.20 m/s2.What is the mass of Zygo? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 2.4 × 1019 kg 
B) 4.8 × 1019 kg 
C) 1.2 × 1020 kg 
D) 2.4 × 1020 kg 
E) 4.8 × 1020 kg 
A) 2.4 × 1019 kg 
B) 4.8 × 1019 kg 
C) 1.2 × 1020 kg 
D) 2.4 × 1020 kg 
E) 4.8 × 1020 kg

Question 6

Two planets have the same surface gravity,but planet B has twice the mass of planet A.If planet A has radius r,what is the radius of planet B?

Accepted Answer

A) r/   
B) r 
C) r   
D) 4r 
E) 2r 
A) r/   
B) r 
C) r   
D) 4r 
E) 2r

Question 7

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 x 1026 kg,and use an orbital radius of 1.00 x 105 km.(G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 19.5 km/s 
B) 27.5 km/s 
C) 13.8 km/s 
A) 19.5 km/s 
B) 27.5 km/s 
C) 13.8 km/s

Question 8

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.54g? (G = 6.67 × 10-11 N ∙ m2/kg2,Mearth = 5.97 × 1024 kg,Rearth = 6.38 × 106 m)

Accepted Answer

A) 2300 km 
B) 1700 km 
C) 5400 km 
D) 2900 km 
A) 2300 km 
B) 1700 km 
C) 5400 km 
D) 2900 km

Question 9

Two small objects,with masses m and M,are originally a distance r apart,and the magnitude of the gravitational force on each one is F.The masses are changed to 2m and 2M,and the distance is changed to 4r.What is the magnitude of the new gravitational force?

Accepted Answer

A) F/16 
B) F/4 
C) 16F 
D) 4F 
E) F/2 
A) F/16 
B) F/4 
C) 16F 
D) 4F 
E) F/2

Question 10

The earth has radius R.A satellite of mass 100 kg is in orbit at an altitude of 3R above the earth's surface.What is the satellite's weight at the altitude of its orbit?

Accepted Answer

A) 61 N 
B) 110 N 
C) 9000 N 
D) 16,000 N 
A) 61 N 
B) 110 N 
C) 9000 N 
D) 16,000 N

Question 11

A satellite having orbital speed V orbits a planet of mass M.If the planet had half as much mass,the orbital speed of the satellite at the same distance from the center would be

Accepted Answer

A) V   . 
B) 2V. 
C) V. 
D) V/   . 
E) V/2. 
A) V   . 
B) 2V. 
C) V. 
D) V/   . 
E) V/2.

Question 12

A satellite that is in a circular orbit 230 km above the surface of the planet Zeeman-474 has an orbital period of 89 min.The radius of Zeeman-474 is 6.38 × 106 m.What is the mass of this planet? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 5.0 × 1024 kg 
B) 5.5 × 1024 kg 
C) 6.0 × 1024 kg 
D) 6.5 × 1024 kg 
A) 5.0 × 1024 kg 
B) 5.5 × 1024 kg 
C) 6.0 × 1024 kg 
D) 6.5 × 1024 kg

Question 13

The radius of the earth is R.At what distance above the earth's surface will the acceleration of gravity be 4.9 m/s2?

Accepted Answer

A) 0.41 R 
B) 0.50 R 
C) 1.00 R 
D) 1.41 R 
E) 0.25 R 
A) 0.41 R 
B) 0.50 R 
C) 1.00 R 
D) 1.41 R 
E) 0.25 R

Question 14

An piece of space debris is released from rest at an altitude that is two earth radii from the center of the earth.Compared to its weight on Earth,the weight of this debris is

Accepted Answer

A) zero. 
B) the same as on the surface of the earth. 
C) one-half of its weight on the surface of the earth. 
D) one-third of its weight on the surface of the earth. 
E) one-quarter of its weight on the surface of the earth. 
A) zero. 
B) the same as on the surface of the earth. 
C) one-half of its weight on the surface of the earth. 
D) one-third of its weight on the surface of the earth. 
E) one-quarter of its weight on the surface of the earth.

Question 15

Two planets have the same surface gravity,but planet B has twice the radius of planet A.If planet A has mass m,what is the mass of planet B?

Accepted Answer

A) m/   
B) m 
C) m   
D) 4m 
E) m/4 
A) m/   
B) m 
C) m   
D) 4m 
E) m/4

Question 16

Asteroid Ida was photographed by the Galileo spacecraft in 1993,and the photograph revealed that the asteroid has a small moon,which has been named Dactyl.From the dimensions of Ida and its general features,one can estimate the mass of Ida to be 4.5 × 1016 kg,and the distance between Dactyl and Ida is approximately 90 km.Assuming a circular orbit,what would be the orbital speed of Dactyl? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 5.8 m/s 
B) 11 m/s 
C) 2.3 m/s 
D) 2.9 m/s 
E) 30 m/s 
A) 5.8 m/s 
B) 11 m/s 
C) 2.3 m/s 
D) 2.9 m/s 
E) 30 m/s

Question 17

Two small balls,A and B,attract each other gravitationally with a force of magnitude F.If we now double both masses and the separation of the balls,what will now be the magnitude of the attractive force on each one?

Accepted Answer

A) 16F 
B) 8F 
C) 4F 
D) F 
E) F/4 
A) 16F 
B) 8F 
C) 4F 
D) F 
E) F/4

Question 18

Mithra is an unknown planet that has two moons,A and B,in circular orbits around it.The table summarizes the hypothetical data about these moons.What is the magnitude of the maximum gravitational force that Moon A exerts on Moon B? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 1.6 × 1013 N 
B) 4.4 × 1013 N 
C) 1.0 × 1014 N 
D) 2.0 × 1014 N 
E) 4.0 × 1014 N 
A) 1.6 × 1013 N 
B) 4.4 × 1013 N 
C) 1.0 × 1014 N 
D) 2.0 × 1014 N 
E) 4.0 × 1014 N

Question 19

You are the science officer on a visit to a distant solar system.Prior to landing on a planet you measure its diameter to be 1.8 × 107 m.You have previously determined that the planet orbits 2.9 × 1011 m from its star with a period of 402 earth days.Once on the surface you find that the acceleration due to gravity is 19.5 m/s2.What are the masses of (a)the planet and (b)the star? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) (a)2.4 kg ×   kg,(b)1.2 kg ×
  kg 
B) (a)4.3 kg ×   kg,(b)1.2 kg ×
  kg 
C) (a)2.4 kg ×   kg,(b)7.1 kg ×
  kg 
D) (a)4.3 kg ×   kg,(b)7.1 kg ×
  kg 
A) (a)2.4 kg ×   kg,(b)1.2 kg ×
  kg 
B) (a)4.3 kg ×   kg,(b)1.2 kg ×
  kg 
C) (a)2.4 kg ×   kg,(b)7.1 kg ×
  kg 
D) (a)4.3 kg ×   kg,(b)7.1 kg ×
  kg

Question 20

In another solar system,a planet has a moon that is 4.0 × 105 m in diameter.Measurements reveal that this moon takes 3.0 x 105 s to make each orbit of diameter 1.8 × 108 m.What is the mass of the planet? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 1.2 × 1024 kg 
B) 1.7 × 1024 kg 
C) 2.4 × 1024 kg 
D) 3.4 × 1024 kg 
E) 4.8 × 1024 kg 
A) 1.2 × 1024 kg 
B) 1.7 × 1024 kg 
C) 2.4 × 1024 kg 
D) 3.4 × 1024 kg 
E) 4.8 × 1024 kg

Exam 12: Gravity

A spaceship is traveling to the Moon.At what point is it beyond the pull of Earth's gravity?

A spherically symmetric planet has four times the earth's mass and twice its radius.If a jar of peanut butter weighs 12 N on the surface of the Earth,how much would it weigh on the surface of this planet?

A satellite of mass M takes time T to orbit a planet.If the satellite had twice as much mass,the time for it to orbit the planet at the same altitude would be

The mass of Pluto is 1.31 × 1022 kg and its radius is 1.15 × 106 m.What is the acceleration of a freely-falling object at the surface of Pluto if it has no atmosphere? (G = 6.67 × 10-11 N ∙ m2/kg2)

In another solar system,a planet has an airless moon Zygo that is 4.0 × 105 m in diameter.Experiments reveal that a freely falling object at the surface of Zygo accelerates at 0.20 m/s2.What is the mass of Zygo? (G = 6.67 × 10-11 N ∙ m2/kg2)

Two planets have the same surface gravity,but planet B has twice the mass of planet A.If planet A has radius r,what is the radius of planet B?

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 x 1026 kg,and use an orbital radius of 1.00 x 105 km.(G = 6.67 × 10-11 N ∙ m2/kg2)

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.54g? (G = 6.67 × 10-11 N ∙ m2/kg2,Mearth = 5.97 × 1024 kg,Rearth = 6.38 × 106 m)

Two small objects,with masses m and M,are originally a distance r apart,and the magnitude of the gravitational force on each one is F.The masses are changed to 2m and 2M,and the distance is changed to 4r.What is the magnitude of the new gravitational force?

The earth has radius R.A satellite of mass 100 kg is in orbit at an altitude of 3R above the earth's surface.What is the satellite's weight at the altitude of its orbit?

A satellite having orbital speed V orbits a planet of mass M.If the planet had half as much mass,the orbital speed of the satellite at the same distance from the center would be

A satellite that is in a circular orbit 230 km above the surface of the planet Zeeman-474 has an orbital period of 89 min.The radius of Zeeman-474 is 6.38 × 106 m.What is the mass of this planet? (G = 6.67 × 10-11 N ∙ m2/kg2)

The radius of the earth is R.At what distance above the earth's surface will the acceleration of gravity be 4.9 m/s2?

An piece of space debris is released from rest at an altitude that is two earth radii from the center of the earth.Compared to its weight on Earth,the weight of this debris is

Two planets have the same surface gravity,but planet B has twice the radius of planet A.If planet A has mass m,what is the mass of planet B?

Two small balls,A and B,attract each other gravitationally with a force of magnitude F.If we now double both masses and the separation of the balls,what will now be the magnitude of the attractive force on each one?

Mithra is an unknown planet that has two moons,A and B,in circular orbits around it.The table summarizes the hypothetical data about these moons.What is the magnitude of the maximum gravitational force that Moon A exerts on Moon B? (G = 6.67 × 10-11 N ∙ m2/kg2)

In another solar system,a planet has a moon that is 4.0 × 105 m in diameter.Measurements reveal that this moon takes 3.0 x 105 s to make each orbit of diameter 1.8 × 108 m.What is the mass of the planet? (G = 6.67 × 10-11 N ∙ m2/kg2)

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric

Electric Current and Direct-Current Circuits

Magnetism

Magnetic Flux and Faradays Law of Induction

Alternating-Current Circuits

Electromagnetic Waves

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

The mass of Pluto is 1.31 × 10²² kg and its radius is 1.15 × 10⁶ m.What is the acceleration of a freely-falling object at the surface of Pluto if it has no atmosphere? (G = 6.67 × 10^-11 N ∙ m²/kg²)

In another solar system,a planet has an airless moon Zygo that is 4.0 × 10⁵ m in diameter.Experiments reveal that a freely falling object at the surface of Zygo accelerates at 0.20 m/s².What is the mass of Zygo? (G = 6.67 × 10^-11 N ∙ m²/kg²)

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 x 10²⁶ kg,and use an orbital radius of 1.00 x 10⁵ km.(G = 6.67 × 10^-11 N ∙ m²/kg²)

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.54g? (G = 6.67 × 10^-11 N ∙ m²/kg²,M_earth = 5.97 × 10²⁴ kg,R_earth = 6.38 × 10⁶ m)

A satellite that is in a circular orbit 230 km above the surface of the planet Zeeman-474 has an orbital period of 89 min.The radius of Zeeman-474 is 6.38 × 10⁶ m.What is the mass of this planet? (G = 6.67 × 10^-11 N ∙ m²/kg²)

The radius of the earth is R.At what distance above the earth's surface will the acceleration of gravity be 4.9 m/s²?

Mithra is an unknown planet that has two moons,A and B,in circular orbits around it.The table summarizes the hypothetical data about these moons.What is the magnitude of the maximum gravitational force that Moon A exerts on Moon B? (G = 6.67 × 10^-11 N ∙ m²/kg²)

In another solar system,a planet has a moon that is 4.0 × 10⁵ m in diameter.Measurements reveal that this moon takes 3.0 x 10⁵ s to make each orbit of diameter 1.8 × 10⁸ m.What is the mass of the planet? (G = 6.67 × 10^-11 N ∙ m²/kg²)