Halliday/Resnick/Walker Fundamentals of Physics 8 th edition

Halliday/Resnick/WalkerFundamentals of Physics 8th edition • Classroom Response System Questions Chapter 13 Gravitation Reading Quiz Questions

13.2.1. Complete the following statement: Near the surface of the earth, the weight of an object a) is the same as the mass of the object. b) is the gravitational force of the earth on the object. c) has the same value regardless of the altitude above the surface of the earth. d) has the same value regardless of the mass of the object.

13.2.2. A rock is thrown straight up from the earth's surface. Which one of the following statements concerning the net force acting on the rock at the top of its path is true? a) It is instantaneously equal to zero newtons. b) It is greater than the weight of the rock. c) It is less than the weight of the rock, but greater than zero newtons. d) Its direction changes from up to down. e) It is equal to the weight of the rock.

13.2.3. Two objects with masses m and M are separated by a distance d. If the distance between the objects is increased to 4d, how does the gravitational force between them change? a) The force will be one-half as great. b) The force will be one-forth as great. c) The force will be one-sixteenth as great. d) The force will be four times as great. e) The force will be sixteen times as great.

13.2.4. Two objects with masses m and M are separated by a distance d. If the separation d remains fixed and the masses of the objects are increased to the values 3m and 3M respectively, how does the gravitational force between them change? a) The force will be nine times as great. b) The force will be three times as great. c) The force will be one-third as great. d) The force will be one-ninth as great. e) It is impossible to determine without knowing the numerical values of m, M, and d.

13.2.5. Which one of the following statements concerning the two "gravitational constants" G, the universal gravitational constant, and g the magnitude of the acceleration due to gravity is true? a) The values of g and G depend on location. b) The values of g and G do not depend on location. c) The value of g is the same everywhere in the universe, but the value of G is not. d) The values of g and G are equal on the surface of any planet, but in general, vary with location in the universe. e) The value of G is the same everywhere in the universe, but the value of g is not.

13.2.6. Which one of the following statements best explains why the weight of an object of mass m is different on Mars than it is on the Earth? a) The mass of Mars is different from that of Earth. b) The mass m is further from the Earth's center when it is on Mars. c) The mass and radius of Mars are both less than those of Earth. d) The mass m will be different on Mars. e) The constant G is different on Mars.

13.2.7. The magnitude of the gravitational force is related to the distance between two objects. Which of the following choices gives the correct relationship between the distance r and the gravitational force? a) r b) r2 c) 1/r d) 1/r2 e) r1/2

13.2.8. Consider the objects of various masses indicated below. The objects are each separated from another object by the distance indicated. In which of these situations is the gravitational force exerted on the two objects the largest? a) #1 b) #2 c) #3 d) #2 and #3 e) #1, #2, and #3

13.3.1. Given a collection of particles, through what process would one determine the net gravitational force on one of the particles due to the others? a) If the number of particles is odd, then the net force on the particle will be zero since every other particle is paired with another particle. b) The gravitational force of the particle nearest the particle will exert the greatest force and the others are negligible. c) Calculate the gravitational force of each particle on the given particle and add them together as vectors to find the net force. d) Calculate the gravitational force of each particle on the given particle and use the vector cross product to find the net force. e) Multiply the mass of the particle by 9.8 m/s2.

13.3.2. Consider a system of particles, each of mass m. In which one of the following configurations is the net gravitational force on Particle A the largest? The horizontal or vertical spacing between particles is the same in each case. a) 1 b) 2 c) 3 d) 4 e) 3 and 4 are equally large

13.4.1. Which one of the following choices is not a reason why the acceleration due to gravity g does not have the same value, 9.8 m/s2, everywhere on the surface of the Earth? a) The Earth is rotating about its axis. b) The value of g depends on where the moon is in its orbit. c) The Earth is not spherical. d) The material from which the Earth is composed is not uniformly distributed and is not of uniform density.

13.4.2. Consider an astronaut aboard the International Space Station in orbit around the Earth. Which one of the following statements concerning the gravitational force on the astronaut is true? a) The astronaut experiences a gravitational force that is equal to zero newtons. b) The net gravitational force on the astronaut due to the Earth and the moon is equal to zero newtons. c) The astronaut experiences a gravitational force and a centripetal force of equal magnitude, but in opposite directions, so the net force on the astronaut is zero newtons. d) The astronaut experiences a gravitational force that is less than at the surface of the Earth, but it is greater than zero newtons. e) The astronaut experiences a gravitational force that is the same at that at the surface of the Earth.

13.5.1. Hypothetically speaking, if an object were located at the center of the Earth, the gravitational force on that object of due to the surrounding Earth, assuming matter is uniformly distributed, would have which of the following values? a) The force would be approximately the same value as if the object were on the surface of the Earth. b) The force would be much greater than the value if the object were on the surface of the Earth. c) The force would be somewhat less than the value if the object was on the surface of the Earth, but it would be greater than zero newtons. d) The force would be zero newtons.

13.5.2. Consider the Earth with its mass non-uniformly distributed. Now imagine the hypothetical situation in which a shaft was constructed deep into the Earth’s interior. Which of the following observations concerning the gravitational force on a particle descending the shaft would be true? a) The net gravitational force on the particle would continually decrease as the particle descends the shaft. b) The net gravitational force on the particle would continually increase as the particle descends the shaft. c) The net gravitational force on the particle would initially increase as the particle descends the shaft, but then decrease as it continues its descent. d) The net gravitational force on the particle would initially decrease as the particle descends the shaft, but then increase as it continues its descent. e) At any point below the surface of the Earth, the net gravitational force on the particle would be equal to zero newtons.

13.6.1. The magnitude of the gravitational potential energy is related to the distance from an object of mass M. Which of the following choices gives the correct relationship between the distance r and the gravitational potential energy? a) r b) r2 c) 1/r d) 1/r2 e) r1/2

13.6.2. Consider the objects of various masses indicated below. The objects are each separated from another object by the distance indicated. In which of these situations is the gravitational potential energy of the two objects the smallest? a) #1 b) #2 c) #3 d) #2 and #3 e) #1, #2, and #3

13.7.1. Which one of the following statements concerning Kepler’s Law of Orbits is true? a) All planets move in elliptical orbits, with the Sun at one focus. b) All planets move in circular orbits, with the Sun at the center. c) All planets move in elliptical orbits, with the planet at one focus. d) All planets move in circular orbits around the center of mass of the solar system. e) All planets move in helical orbits, with the Sun at one end of the helix.

13.7.2. Which one of the following statements represents the Law of Areas? a) In their orbits about the Sun, every planet sweeps out the same equal area in the same equal amount of time. b) A line that connects a planet to the Sun sweeps out equal areas in the plane of the planet’s orbit in equal time intervals. c) The surface area of a planet is directly proportional to the square of its orbit about the Sun. d) Every planet sweeps out the same area in a one Earth year period, making one complete orbit about the Sun. e) The area swept by the orbit of the Sun is equal to the sum of the areas swept by the planets during one Earth year period.

13.7.3. Which one of the following statements represents the Law of Periods? a) The orbital period of a satellite in orbit of a planet is inversely proportional to its mass. b) The period of a planet in its orbit about the Sun is directly proportional to the radius of its orbit. c) The rotational period of the Sun equals the sum of the rotational periods of the planets. d) Every planet sweeps out the same area in a one Earth year period, making one complete orbit about the Sun. e) The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.

13.8.1. Consider the orbits shown in the drawing. Each of the orbits has the same length semimajor axis, but differs in the eccentricities, which are given. In which of these orbits would an object have the greatest total mechanical energy, if any? a) All of the orbits have the same total energy. b) e = 0 c) e = 0.5 d) e = 0.8 e) e = 0.9

13.9.1. Which one of the following statements describes the Principle of Equivalence? a) Objects in two different reference frames are equivalent. b) The square of the period of a planet is proportional to the cube of the planet’s semi-major axis. c) All motion is relative. d) All planets move in equivalent elliptical orbits. e) Acceleration and gravitation are equivalent.

13.9.2. To which one of the following is gravity equivalent, according to the Principle of Equivalence? a) velocity b) free-fall c) net force d) acceleration e) energy

Halliday/Resnick/Walker Fundamentals of Physics 8 th edition