Question 1

The reason an astronaut in an earth satellite feels weightless is that

Accepted Answer

A) the astronaut is beyond the range of the earth's gravity. 
B) the astronaut is falling. 
C) the astronaut is at a point in space where the effects of the moon's gravity and the earth's gravity cancel. 
D) this is a psychological effect associated with rapid motion. 
E) the astronaut's acceleration is zero. 
A) the astronaut is beyond the range of the earth's gravity. 
B) the astronaut is falling. 
C) the astronaut is at a point in space where the effects of the moon's gravity and the earth's gravity cancel. 
D) this is a psychological effect associated with rapid motion. 
E) the astronaut's acceleration is zero. B

Question 2

An astronaut is in equilibrium when he is positioned   from the center of asteroid X and   from the center of asteroid Y,along the straight line joining the centers of the asteroids.What is the ratio of the masses X/Y of the asteroids?

Accepted Answer

A) 0.0581 
B) 17.2 
C) 0.241 
D) 4.15 
A) 0.0581 
B) 17.2 
C) 0.241 
D) 4.15 A

Question 3

A satellite is orbiting the earth.If a payload of material is added until it doubles the satellite's mass,the earth's pull of gravity on this satellite will double but the satellite's orbit will not be affected.

Accepted Answer

A) True 
 B)False  True

Question 4

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 and its rotation period to be 22.3 hours.You have previously determined that the planet orbits 1.8 × 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 59.7 m/s2.What are the mass of (a)the planet and (b)the star? (G = 6.67 × 10-11 N ∙ m2/kg2.)

Accepted Answer

A) (a)7.2 kg ×   kg,(b)2.9 kg ×   kg 
B) (a)1.3 kg ×   kg,(b)2.9 kg ×   kg 
C) (a)7.2 kg ×   kg,(b)1.7 kg ×   kg 
D) (a)1.3 kg ×   kg,(b)1.7 kg ×   kg 
A) (a)7.2 kg ×   kg,(b)2.9 kg ×   kg 
B) (a)1.3 kg ×   kg,(b)2.9 kg ×   kg 
C) (a)7.2 kg ×   kg,(b)1.7 kg ×   kg 
D) (a)1.3 kg ×   kg,(b)1.7 kg ×   kg

Question 5

Ekapluto is an unknown planet that has two moons in circular orbits.The table summarizes the hypothetical data about the moons.(G = 6.67 × 10-11 N ∙ m2/kg2)   The mass of Ekapluto is closest to

Accepted Answer

A) 1.0 × 1022 kg. 
B) 3.0 × 1022 kg. 
C) 1.0 × 1023 kg. 
D) 3.0 × 1023 kg. 
E) 1.0 × 1024 kg. 
A) 1.0 × 1022 kg. 
B) 3.0 × 1022 kg. 
C) 1.0 × 1023 kg. 
D) 3.0 × 1023 kg. 
E) 1.0 × 1024 kg.

Question 6

Beings on spherical asteroid Π have observed that a large rock is approaching their asteroid in a collision course.At   from the center of the asteroid,the rock has a speed of   and later at   it has a speed of   Use energy conservation to find the mass of asteroid Π.You can neglect any effects due to the parent star of the asteroid. (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 4.582 ×   kg 
B) 9.164 ×   kg 
C) 6.112 ×   kg 
D) 4.582 ×   kg 
A) 4.582 ×   kg 
B) 9.164 ×   kg 
C) 6.112 ×   kg 
D) 4.582 ×   kg

Question 7

Three identical very small 50-kg masses are held at the corners of an equilateral triangle,0.30 m on each side.If one of the masses is released,what is its initial acceleration if the only forces acting on it are the gravitational forces due to the other two masses? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 3.7 × 10-8 m/s2 
B) 2.5 × 10-8 m/s2 
C) 1.9 × 10-8 m/s2 
D) 4.2 × 10-8 m/s2 
E) 6.4 × 10-8 m/s2 
A) 3.7 × 10-8 m/s2 
B) 2.5 × 10-8 m/s2 
C) 1.9 × 10-8 m/s2 
D) 4.2 × 10-8 m/s2 
E) 6.4 × 10-8 m/s2

Question 8

Sputnik I was launched into orbit around Earth in 1957.It had a perigee (the closest approach to Earth,measured from Earth's center)of 6.81 × 106 m and an apogee (the furthest point from Earth's center)of 7.53 × 106 m.What was its speed when it was at its perigee? The mass of Earth is 5.97 × 1024 kg and G = 6.67 × 10-11 N ∙ m2/kg2.

Accepted Answer

A) 7180 m/s 
B) 7840 m/s 
C) 8230 m/s 
D) 11,000 m/s 
E) 13,400 m/s 
A) 7180 m/s 
B) 7840 m/s 
C) 8230 m/s 
D) 11,000 m/s 
E) 13,400 m/s

Question 9

The moons of Mars,Phobos (Fear)and Deimos (Terror),are very close to the planet compared to Earth's Moon.Their orbital radii are 9,378 km and 23,459 km respectively.What is the ratio of the orbital speed of Phobos to that of Deimos?

Accepted Answer

A) 0.2528 
B) 0.3998 
C) 1.582 
D) 2.858 
E) 3.956 
A) 0.2528 
B) 0.3998 
C) 1.582 
D) 2.858 
E) 3.956

Question 10

Ekapluto is an unknown planet that has two spherical moons in circular orbits.The table summarizes the hypothetical data about the moons.Both moons have low axial spin rates.(G = 6.67 × 10-11 N ∙ m2/kg2)   The acceleration due to gravity at the surface of Moon B is

Accepted Answer

A) 0.10 m/s2. 
B) 0.15 m/s2. 
C) 0.20 m/s2. 
D) 0.25 m/s2. 
E) 0.30 m/s2. 
A) 0.10 m/s2. 
B) 0.15 m/s2. 
C) 0.20 m/s2. 
D) 0.25 m/s2. 
E) 0.30 m/s2.

Question 11

A small-sized 155-kg mass is located 1.50 m from a small-sized 275-kg mass,with both masses fixed in place.Where should you place a third small-sized mass so that the net gravitational force on it due to the original two masses is zero?

Accepted Answer

0.643 m from the 155

Question 12

A certain planet has an escape speed V.If another planet of the same size has twice the mass as the first planet,its escape speed will be

Accepted Answer

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

Question 13

A small planet having a radius of 1000 km exerts a gravitational force of 100 N on an object that is 500 km above its surface.If this object is moved 500 km farther from the planet,the gravitational force on it will be closest to

Accepted Answer

A) 75 N. 
B) 71 N. 
C) 56 N. 
D) 50 N. 
E) 25 N. 
A) 75 N. 
B) 71 N. 
C) 56 N. 
D) 50 N. 
E) 25 N.

Question 14

A baseball is located at the surface of the earth.Which statements about it are correct? (There may be more than one correct choice.)

Accepted Answer

A) The earth exerts a much greater gravitational force on the ball than the ball exerts on the earth. 
B) The ball exerts a greater gravitational force on the earth than the earth exerts on the ball. 
C) The gravitational force on the ball due to the earth is exactly the same as the gravitational force on the earth due to the ball. 
D) The gravitational force on the ball is independent of the mass of the ball. 
E) The gravitational force on the ball is independent of the mass of the earth. 
A) The earth exerts a much greater gravitational force on the ball than the ball exerts on the earth. 
B) The ball exerts a greater gravitational force on the earth than the earth exerts on the ball. 
C) The gravitational force on the ball due to the earth is exactly the same as the gravitational force on the earth due to the ball. 
D) The gravitational force on the ball is independent of the mass of the ball. 
E) The gravitational force on the ball is independent of the mass of the earth.

Question 15

A certain planet has an escape speed V.If another planet has twice size and twice the mass of the first planet,its escape speed will be

Accepted Answer

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

Question 16

A planet has two small satellites in circular orbits around the planet.The first satellite has a period 18.0 hours and an orbital radius 2.00 × 107 m.The second planet has an orbital radius 3.00 × 107 m.What is the period of the second satellite?

Accepted Answer

A) 60.8 h 
B) 12.0 h 
C) 33.1 h 
D) 9.80 h 
E) 27.0 h 
A) 60.8 h 
B) 12.0 h 
C) 33.1 h 
D) 9.80 h 
E) 27.0 h

Question 17

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 × 1026 kg and the rings have an average radius of 100,000 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 
D) 1.95 km/s 
A) 19.5 km/s 
B) 27.5 km/s 
C) 13.8 km/s 
D) 1.95 km/s

Question 18

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 106 m,G = 6.67 × 10-11 N ∙ m2/kg2.)

Accepted Answer

A) -0.60 N 
B) -1.5 N 
C) -2.6 N 
D) -3.6 N 
E) -5.2 N 
A) -0.60 N 
B) -1.5 N 
C) -2.6 N 
D) -3.6 N 
E) -5.2 N

Question 19

The weight of spaceman Speff at the surface of planet X,solely due to its gravitational pull,is 389 N.If he moves to a distance of 1.86 × 104 km above the planet's surface,his weight changes to 24.31 N.What is the mass of planet X,if Speff's mass is 75.0 kg? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 2.99 × 1024 kg 
B) 2.99 × 1018 kg 
C) 2.99 × 1017 kg 
D) 1.59 × 1018 kg 
A) 2.99 × 1024 kg 
B) 2.99 × 1018 kg 
C) 2.99 × 1017 kg 
D) 1.59 × 1018 kg

Question 20

Spaceman Speff orbits spherical asteroid X with his spaceship.To remain in a circular orbit at 421 km from the asteroid's center,he should maintain a speed of   What is the mass of planet X? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A) 4.0 × 1019 kg 
B) 5.1 × 1017 kg 
C) 4.0 × 1016 kg 
D) 5.1 × 1014 kg 
A) 4.0 × 1019 kg 
B) 5.1 × 1017 kg 
C) 4.0 × 1016 kg 
D) 5.1 × 1014 kg

Exam 13: Newtons Theory of Gravity

The reason an astronaut in an earth satellite feels weightless is that

An astronaut is in equilibrium when he is positioned from the center of asteroid X and from the center of asteroid Y,along the straight line joining the centers of the asteroids.What is the ratio of the masses X/Y of the asteroids?

A satellite is orbiting the earth.If a payload of material is added until it doubles the satellite's mass,the earth's pull of gravity on this satellite will double but the satellite's orbit will not be affected.

Ekapluto is an unknown planet that has two moons in circular orbits.The table summarizes the hypothetical data about the moons.(G = 6.67 × 10-11 N ∙ m2/kg2) The mass of Ekapluto is closest to

Three identical very small 50-kg masses are held at the corners of an equilateral triangle,0.30 m on each side.If one of the masses is released,what is its initial acceleration if the only forces acting on it are the gravitational forces due to the other two masses? (G = 6.67 × 10-11 N ∙ m2/kg2)

The moons of Mars,Phobos (Fear)and Deimos (Terror),are very close to the planet compared to Earth's Moon.Their orbital radii are 9,378 km and 23,459 km respectively.What is the ratio of the orbital speed of Phobos to that of Deimos?

Ekapluto is an unknown planet that has two spherical moons in circular orbits.The table summarizes the hypothetical data about the moons.Both moons have low axial spin rates.(G = 6.67 × 10-11 N ∙ m2/kg2) The acceleration due to gravity at the surface of Moon B is

A small-sized 155-kg mass is located 1.50 m from a small-sized 275-kg mass,with both masses fixed in place.Where should you place a third small-sized mass so that the net gravitational force on it due to the original two masses is zero?

A certain planet has an escape speed V.If another planet of the same size has twice the mass as the first planet,its escape speed will be

A small planet having a radius of 1000 km exerts a gravitational force of 100 N on an object that is 500 km above its surface.If this object is moved 500 km farther from the planet,the gravitational force on it will be closest to

A baseball is located at the surface of the earth.Which statements about it are correct? (There may be more than one correct choice.)

A certain planet has an escape speed V.If another planet has twice size and twice the mass of the first planet,its escape speed will be

A planet has two small satellites in circular orbits around the planet.The first satellite has a period 18.0 hours and an orbital radius 2.00 × 107 m.The second planet has an orbital radius 3.00 × 107 m.What is the period of the second satellite?

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 × 1026 kg and the rings have an average radius of 100,000 km.(G = 6.67 × 10-11 N ∙ m2/kg2)

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 106 m,G = 6.67 × 10-11 N ∙ m2/kg2.)

The weight of spaceman Speff at the surface of planet X,solely due to its gravitational pull,is 389 N.If he moves to a distance of 1.86 × 104 km above the planet's surface,his weight changes to 24.31 N.What is the mass of planet X,if Speff's mass is 75.0 kg? (G = 6.67 × 10-11 N ∙ m2/kg2)

Spaceman Speff orbits spherical asteroid X with his spaceship.To remain in a circular orbit at 421 km from the asteroid's center,he should maintain a speed of What is the mass of planet X? (G = 6.67 × 10-11 N ∙ m2/kg2)

Concepts of Motion

Kinematics in One Dimension

Vectors and Coordinate Systems

Kinematics in Two Dimensions

Force and Motion

Dynamics I: Motion Along a Line

Newtons Third Law

Dynamics II: Motion in a Plane

Work and Kinetic Energy

Interactions and Potential Energy

Impulse and Momentum

Rotation of a Rigid Body

Fluids and Elasticity

Oscillations

Traveling Waves

Superposition

A Macroscopic Description of Matter

Work, heat, and the First Law of Thermodynamics

The Micromacro Connection

Heat Engines and Refrigerators

Electric Charges and Forces

The Electric Field

Gausss Law

The Electric Potential

Potential and Field

Current and Resistance

Fundamentals of Circuits

The Magnetic Field

Electromagnetic Induction

Electromagnetic Fields and Waves

Ac Circuits

Wave Optics

Ray Optics

Optical Instruments

Relativity

The Foundations of Modern Physics

Quantization

Wave Functions and Uncertainty

One-Dimensional Quantum Mechanics

Atomic Physics

Nuclear Physics

Filters

Ekapluto is an unknown planet that has two moons in circular orbits.The table summarizes the hypothetical data about the moons.(G = 6.67 × 10^-11 N ∙ m²/kg²) The mass of Ekapluto is closest to

Ekapluto is an unknown planet that has two spherical moons in circular orbits.The table summarizes the hypothetical data about the moons.Both moons have low axial spin rates.(G = 6.67 × 10^-11 N ∙ m²/kg²) The acceleration due to gravity at the surface of Moon B is

A planet has two small satellites in circular orbits around the planet.The first satellite has a period 18.0 hours and an orbital radius 2.00 × 10⁷ m.The second planet has an orbital radius 3.00 × 10⁷ m.What is the period of the second satellite?

Find the orbital speed of an ice cube in the rings of Saturn.The mass of Saturn is 5.68 × 10²⁶ kg and the rings have an average radius of 100,000 km.(G = 6.67 × 10^-11 N ∙ m²/kg²)

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 10⁶ m,G = 6.67 × 10^-11 N ∙ m²/kg².)

The weight of spaceman Speff at the surface of planet X,solely due to its gravitational pull,is 389 N.If he moves to a distance of 1.86 × 10⁴ km above the planet's surface,his weight changes to 24.31 N.What is the mass of planet X,if Speff's mass is 75.0 kg? (G = 6.67 × 10^-11 N ∙ m²/kg²)

Spaceman Speff orbits spherical asteroid X with his spaceship.To remain in a circular orbit at 421 km from the asteroid's center,he should maintain a speed of What is the mass of planet X? (G = 6.67 × 10^-11 N ∙ m²/kg²)