Chapter 9 ( Gravity) Test Review

A weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above the Earth's surface (Thus the distance doubles) . How much would she weigh there? A) 0 B) 100 N C) 200 N D) 400 N E) none of these

B) 100 N

If the moon were covered with water, tidal effects caused by the Earth would find the moon with A) 1 tidal bulge. B) 2 tidal bulges. C) 3 tidal bulges. D) 4 tidal bulges. E) no tidal bulges.

B) 2 tidal bulges.

asteroid exerts a 360-N gravitational force on a nearby spacecraft. If the spacecraft moves to a position three times as far from the center of the asteroid, the force will be A) zero. B) 40 N. C) 120 N. D) 360 N. E) 1080 N.

B) 40 N.

During an eclipse of the sun the high ocean tides on Earth are A) extra high. B) extra low. C) not particularly different.

A) extra high.

The direction of a gravitational field is A) in the same direction as the gravitational attraction. B) away from the center of gravity of an object. C) opposite to the direction of gravitational attraction.

A) in the same direction as the gravitational attraction.

If the mass of the Earth somehow increased with no change in radius, your weight would A) increase also. B) decrease. C) stay the same.

A) increase also.

If the radius of the Earth somehow decreased with no change in mass, your weight would A) increase. B) not change. C) decrease.

A) increase.

Two objects move toward each other because of gravity. As the objects get closer and closer, the force between them A) increases. B) decreases. C) increases, then decreases. D) decreases, then increases. E) remains constant.

A) increases.

Which is most responsible for the ocean tides? A) the moon B) the sun C) Both contribute equally.

A) the moon

An asteroid exerts a 360-N gravitational force on a nearby spacecraft. This force is directed A) toward the asteroid. B) away from the asteroid. C) toward the sun.

A) toward the asteroid.

According to Newton, the greater the masses of interacting objects, the A) less the gravitational force between them. B) greater the gravitational force between them. C) greater the force between them by the square of the masses.

B) greater the gravitational force between them.

The main reason ocean tides exist is that the pull of the moon A) and sun are in conjunction at high tides and in opposition at low tides. B) is greater on oceans closer to the moon and less on oceans farther from the moon. C) is greater on the Earth because the moon is closer to Earth. D) and the sun on the oceans are in opposite directions. E) none of these

B) is greater on oceans closer to the moon and less on oceans farther from the moon.

A hollow spherical planet is inhabited by people who live inside it, where the gravitational field is zero. When a very massive space ship lands on the planet's surface, inhabitants find that the gravitational field inside the planet is A) still zero. B) non-zero, directed toward the spaceship. C) non-zero, directed away from the spaceship.

B) non-zero, directed toward the spaceship.

If you drop a stone into a hole drilled all the way to the other side of the Earth (neglect the molten core), the stone will A) come to an abrupt stop at the center of the Earth. B) speed up until it gets to the center of the Earth. C) speed up until it reaches the other side of the Earth. D) slow down until it reaches the center.

B) speed up until it gets to the center of the Earth.

When you step on a weighing scale at noon, the Earth pulls you down and the overhead sun pulls you upward. The reason the sun's pull doesn't decrease your weight at noon is because A) the sun's pull on you is negligibly small. B) the weighing scale is calibrated only in Earth weight. C) you, the scale, and the Earth are in free fall (in orbit) around the sun. D) the sun's pull is cancelled by the gravitation of other celestial bodies. E) of tidal effects in the "solid" Earth.

C) you, the scale, and the Earth are in free fall (in orbit) around the sun.

When the distance between two stars decreases by half, the force between them A) decreases by one-quarter. B) decreases by one-half. C) increases to twice as much. D) increases to four times as much. E) stays the same.

D) increases to four times as much.

The factor most directly responsible for making a black hole invisible is its A) size. B) mass. C) color. D) surface escape velocity. E) none of these

D) surface escape velocity.

All places on the Earth would have high tides at the same instant if the A) moon did not revolve. B) moon did not rotate. C) sun did not revolve. D) sun did not rotate. E) None of the above choices are correct.

E) None of the above choices are correct

Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them is also doubled, then the force between them is A) one quarter. B) half as much. C) twice as much. D) four times as much. E) none of these

E) none of these

Inside a freely falling runaway elevator, your A) acceleration is zero. B) apparent weight is zero. C) gravitational interaction with the Earth is zero. D) all of these E) none of these

B) apparent weight is zero.

If the Earth's mass decreased to one-half its original mass with no change in radius, then your weight would A) decrease to one quarter your original weight. B) decrease to one half your original weight. C) stay the same. D) none of these

B) decrease to one half your original weight.

Newton discovered A) gravity. B) that gravity is universal. C) neither

B) that gravity is universal.

Which pulls on the oceans of the Earth with the greater force? A) the moon B) the sun C) Both pull the same.

B) the sun

What is the force of gravity on a 500-newton woman standing on the Earth's surface? A) 50 N B) 250 N C) 500 N D) 5000 N E) none of thes

C) 500 N

A very massive object A and a less massive object B move toward each other under the influence of gravitation. Which force, if either, is greater? A) the force on A B) the force on B C) Both forces are the same.

C) Both forces are the same.

The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because A) your mass is 100 times less on Jupiter. B) Jupiter is significantly farther from the sun. C) Jupiter's radius is 10 times the Earth's radius. D) you are 100 times more weightless there. E) none of these

C) Jupiter's radius is 10 times the Earth's radius.

No force due to Earth's gravity is acting on the astronauts inside the orbiting space shuttle. This statement is A) always true while in orbit. B) sometimes true while in orbit. C) always false.

C) always false.

If the sun were twice as massive A) its pull on the Earth would double. B) the pull of the Earth on the sun would double. C) both of these D) neither of these

C) both of these

According to Newton, doubling the distance between two interacting objects A) divides by 2 the gravitational force between them. B) multiplies by 2 the gravitational force between them. C) divides by 4 the gravitational force between them. D) multiplies by 4 the gravitational force between them.

C) divides by 4 the gravitational force between them.

If the sun somehow became twice as massive, your weight as normally measured here on Earth would A) double. B) quadruple. C) not change.

C) not change

If your mass, the mass of the Earth, and the mass of everything in the solar system were twice as much as it is now, yet everything stayed the same size, your weight on Earth would A) be the same. B) double. C) quadruple. D) be eight times as much as now. E) none of these

C) quadruple.

When a star collapses to form a black hole, its mass A) increases. B) decreases. C) remains the same.

C) remains the same.

A black hole is A) an empty region of space with a huge gravitational field. B) a small region that contains the mass of many galaxies. C) simply the remains of a giant star that has undergone gravitational collapse.

C) simply the remains of a giant star that has undergone gravitational collapse.

If the sun collapsed to a black hole, the Earth's gravitational attraction to it would be A) more. B) less. C) the same.

C) the same.

Tidal forces in general are the result of A) two or more sources of gravitation. B) a combination of any kind of forces acting on a body. C) unequal forces acting on different parts of a body. D) the inverse-square law. E) unequal fluid flow.

C) unequal forces acting on different parts of a body.

There would be only one ocean tide per 24-hour day if the A) Earth and moon were equally massive. B) moon were more massive than the Earth. C) sun's influence on the tides were negligible. D) moon's mass were small - only a few kilograms. E) none of these

E) none of these

Half way to the center of a completely hollow planet with a thin uniform shell, your weight would be A) one-quarter of your weight on the surface. B) one-half of your weight on the surface. C) three-quarters of your weight on the surface. D) the same as at the surface. E) zero.

E) zero