Chapter 9

A. Each of the following diagrams shows a spaceship somewhere along the way between Earth and the Moon (not to scale); the midpoint of the distance is marked to make it easier to see how the locations compare. Assume the spaceship has the same mass throughout the trip (that is, it is not burning any fuel). Rank the five positions of the spaceship from left to right based on the strength of the gravitational force that Earth exerts on the spaceship, from strongest to weakest. B. The following diagrams are the same as those from Part A. This time, rank the five positions of the spaceship from left to right based on the strength of the gravitational force that the Moon exerts on the spaceship, from strongest to weakest.

Strongest Force: Is Spaceship closest to earth Weakest Force: Closest to moon Strongest Force: Spaceship is closest to moon Weakest Force: Closest to earth

What would be the path of the Moon if somehow all gravitational forces on it vanished to zero?

The path of the moon would move in a straight line, instead of circling both the sun and earth.

The planet and its moon gravitationally attract each other. Rank the force of attraction between each pair from greatest to leas

Greatest 2m-D-m = M-D-2m M=D=M M=2D=2M Least

Rank the microtidal forces on your own body, from greatest to least, produced by the following:

Greatest Earth Sun Neptune Least

If the Moon pulls Earth as strongly as Earth pulls the Moon, why doesn't Earth rotate around the Moon, or why don't both rotate around a point midway between them?

The moon makes up a smaller mass than the earth does and they have to rotate at a central point

A. How does the gravity in the Space Shuttle compare with the gravity on Earth's surface? B. Why does the gravity in the Space Shuttle compare with the gravity on Earth the way it does? C.Why do the astronauts in the Space Shuttle float around?

A. The gravity in the Space Shuttle is approximately equal to the gravity on the surface of the Earth. B. The Space Shuttle and the surface of the Earth are about the same distance from the center of the Earth. C. The Space Shuttle is in free fall, so the shuttle and the astronauts inside it are continuously falling toward the Earth. They thus experience apparent weightlessness.

What is the magnitude of the gravitational force between two 1-kg bodies that are 1 m apart?

6.67 × 10 -11 N

A. Predict how the upward force exerted on the feet by the scale will compare to the weight of the man if the elevator is moving upward at a constant speed. B. Predict how the upward force exerted on the feet by the scale will compare to the man's weight if the elevator is moving downward at a constant speed. C. Predict how the upward force exerted on the feet by the scale will compare to the man's weight if the elevator is accelerating upward. D. Predict how the upward force exerted on the feet by the scale will compare to the man's weight if the elevator is accelerating downward.

A. The upward force on the feet will be equal to the man's weight. B. The upward force on the feet will be equal to the man's weight. C. The upward force on the feet will exceed the man's weight. D. The upward force on the feet will be less than the man's weight.

Calculate the force of gravity on the 1-kg mass if it were 1.3×107 m above Earth's surface (that is, if it were three Earth radii from Earth's center).

F = 1.1 N

Find the change in the gravitational force between two planets if the masses of both planets are doubled but the distance between them stays the same.

Fnew/F = 4

The following diagrams show five pairs of asteroids, labeled with their relative masses (M) and distances (d) between them. For example, an asteroid with M=2 has twice the mass of one with M=1 and a distance of d=2 is twice as large as a distance of d=1. Rank each pair from left to right based on the strength of the gravitational force attracting the asteroids to each other, from strongest to weakest.

Strongest Force: M=2--D=1--M=2 M=1--D=1--M=2 M=1--D=1--M=1 M=1--D=2--M=2 M=1--D=2--M=1 Weakest Force

Most people today know that the ocean tides are caused principally by the gravitational influence of the Moon, and most people therefore think that the gravitational pull of the Moon on Earth is greater than the gravitational pull of the Sun on Earth. What do you think?

The gravitational pull of the sun on the earth is greater than the gravitational pull on the moon. The ocean tides are caused by the differences in gravitational forces by the moon on the opposite sides of the earth.

Where do you weigh more: at the bottom of Death Valley or atop one of the peaks of the Sierra Nevada? Why?

You weigh more in Death Valley because you are closer to the center of Earth.

The constant G in Newton's equation _______.

makes the units of measurement consistent

A. Which of the following quantities represent mass? B. Which of the following quantities would be acceptable representations of weight? C.The gravitational field on the surface of the earth is stronger than that on the surface of the moon. If a rock is transported from the moon to the earth, which properties of the rock change? D. An object is lifted from the surface of a spherical planet to an altitude equal to the radius of the planet. As a result, which of the following changes in the properties of the object take place? E. If acceleration due to gravity on the earth is g, which formula gives the acceleration due to gravity on Loput? F. If the acceleration due to gravity on the earth is 9.8 m/s2, what is the acceleration due to gravity on Rams? G. Which planet should Punch travel to if his goal is to weigh in at 118 lb? Refer to the table of planetary masses and radii given to determine your answer. H. After Punch Taut travels to Pentune, what actually happens to his mass and his weight?

A. 120 kg, 0.34 g B. 12.0 lbs, 1600 kN, 899 MN C. weight only D. mass remains the same; weight decreases E. g=5.6/1.72^2 F. 5.7 m/s^2 G. Pentune H. mass remains the same; weight decreases

A. Suppose you are in an elevator. As the elevator starts upward, its speed will increase. During this time when the elevator is moving upward with increasing speed, your weight will be __________. B. Suppose you are in an elevator that is moving upward. As the elevator nears the floor at which you will get off, its speed slows down. During this time when the elevator is moving upward with decreasing speed, your weight will be __________. C. As you found in Part A, your weight will be greater than normal when the elevator is moving upward with increasing speed. For what other motion would your weight also be greater than your normal weight? D. If you are standing on a scale in an elevator, what exactly does the scale measure?

A. greater than your normal weight at rest B. less than your normal weight at rest C. The elevator moves downward while slowing in speed. D. the force you exert on the scale

A. The following five diagrams show pairs of astronomical objects that are all separated by the same distance d. Assume the asteroids are all identical and relatively small, just a few kilometers across. Considering only the two objects shown in each pair, rank the strength, from strongest to weakest, of the gravitational force acting on the asteroid on the left. B. The following diagrams are the same as those from Part A. Again considering only the two objects shown in each pair, this time rank the strength, from strongest to weakest, of the gravitational force acting on the object on the right. C. The following diagrams are the same as those from Part A. This time, rank the pairs from left to right based on the size of the acceleration the asteroid on the left would have due to the gravitational force exerted on it by the object on the right, from largest to smallest. D. Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion __________.

ABC. Strongest Force- Asteroid--Sun Asteroid--Earth Asteroid--Moon Asteroid--Asteroid Asteriod--Hydrogen Atom Weakest Force D. the Moon has a larger acceleration than Earth, because it has a smaller mass