Question 1

What is the magnitude and direction of the gravitational force that acts on a person who weighs 500 N at the Earth's surface?

Accepted Answer

500 N straight downward, which is the weight of the person.

Question 2

If the masses of two planets doubles and the distance between them also doubles, the force between them would be
A)one-quarter.
B)half as much.
C)twice as much.
D)four times as much.
E)none of the above

Accepted Answer

E

Question 3

Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them
A)increases.
B)decreases.
C)remains constant.

Accepted Answer

According to the law of universal gravitation, the force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. As the objects move closer together, the distance between them decreases, causing the force of gravity to increase.

Question 4

Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them doesn't change, 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 the above

Accepted Answer

According to Newton's Law of Gravitation, the force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. If both masses are doubled and the distance remains the same, the force between them will increase by a factor of 2 x 2 / 1^2 = 4. Therefore, the correct answer is D: four times as much.

Question 5

If your mass remains unchanged while both the mass of Earth and its radius doubles, your weight
A)remains the same.
B)doubles.
C)quadruples.
D)increases by eight times.
E)reduces by half.

Accepted Answer

Weight is determined by the gravitational force, which is proportional to the mass of the Earth and inversely proportional to the square of its radius. If both the mass and radius of the Earth double, the gravitational force (and thus weight) is halved.

Question 6

Two objects move toward each other due to gravity. As the objects get closer and closer, the acceleration of each
A)increases.
B)decreases.
C)remains constant.

Accepted Answer

As the objects get closer, the force of gravity between them increases. This directly results in an increase in acceleration. The equation for gravitational force is F= G ((m1*m2)/r^2) where G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between their centers of mass. When the distance between them decreases, the force of gravity increases and so does the acceleration. Therefore, the acceleration of each object increases as they get closer and closer.

Question 7

If your mass remained the same while the mass of Earth doubled while staying the same size, your weight would
A)be the same.
B)double.
C)quadruple.
D)be eight times as much as now.
E)none of the above

Accepted Answer

Your weight would double because weight is the force of gravity acting on an object, which is directly proportional to the mass of the Earth. Doubling Earth's mass would double the gravitational force, thus doubling your weight.

Question 8

According to Newton, the closer gravitationally interacting objects are to each other, the
A)less the gravitational force between them.
B)more the gravitational force between them.
C)constancy of the force between them.

Accepted Answer

According to Newton's law of gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Therefore, the closer the objects are, the stronger the gravitational force between them.

Question 9

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.

Accepted Answer

According to Newton's law of gravitation, the gravitational force between two objects is directly proportional to the masses of the objects. This means that the greater the masses of interacting objects, the greater the gravitational force between them. Therefore, the correct choice is B.

Question 10

According to Newton, the greater the distance between gravitationally interacting objects, the
A)less the gravitational force between them.
B)more the gravitational force between them.
C)constancy of the force between them.

Accepted Answer

According to Newton's law of universal gravitation, the force of attraction between two objects decreases as the distance between them increases. Specifically, the force decreases as the square of the distance between the objects (i.e. an inverse square law). Therefore, the greater the distance between gravitationally interacting objects, the less the gravitational force between them.

Question 11

If the Earth had twice its present radius and twice its present mass, what would happen to your weight? Explain.

Accepted Answer

The answer of If the Earth had twice its present...

Question 12

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

Accepted Answer

Weight is directly proportional to the mass of the object and the gravitational force acting on it. Since the gravitational force between two objects is directly proportional to the product of their masses, an increase in Earth's mass would result in an increase in the gravitational force acting on an object on its surface. Therefore, your weight would increase as well.

Question 13

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

Accepted Answer

Newton discovered that gravity is not just a force that occurs on Earth, but rather, it is a force that exists universally and affects all objects in the universe.

Question 14

If Earth's mass doubled with no change in radius, your weight would
A)increase by one-quarter.
B)double.
C)be four times as much.
D)none of the above

Accepted Answer

The answer of If Earth's mass doubled with no change...

Question 15

Consider two planets in space that gravitationally attract each other. If the mass of one planet is doubled, and the distance between them doesn't change, 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 the above

Accepted Answer

The gravitational force between two masses is directly proportional to the product of their masses. Therefore, if the mass of one planet is doubled, the gravitational force between them also doubles.

Question 16

How is stepping off a curb similar to taking a ride aboard the space shuttle?

Accepted Answer

The answer of How is stepping off a curb similar...

Question 17

If the masses of two planets doubles and the distance between reduces by half, the force between them would be
A)unchanged.
B)half as much.
C)twice as much.
D)four times as much.
E)none of the above

Accepted Answer

The answer of If the masses of two planets doubles...

Question 18

The Earth and the Moon gravitationally attract each other. Does the more massive Earth attract the Moon with a greater force, the same force, or less force than the Moon attracts the Earth? What reasoning guides your answer?

Accepted Answer

The answer of The Earth and the Moon gravitationally attract...

Question 19

What is the force of gravity on a 500-N woman standing on Earth's surface?
A)50 N
B)250 N
C)500 N
D)598 N
E)5000 N

Accepted Answer

The force of gravity on an object, often referred to as weight, is already given as 500 N. This means the force of gravity acting on the woman is 500 N, as weight is a measure of the gravitational force exerted on an object.

Question 20

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

Accepted Answer

Weight is proportional to mass, so if the mass of the Earth decreases to one-half its original mass, then the force of gravity on an object on the surface of the Earth (i.e. weight) will decrease proportionally. Therefore, your weight would decrease to one-half.

Quiz 4: Gravity, Projectiles, and Satellites

What is the magnitude and direction of the gravitational force that acts on a person who weighs 500 N at the Earth's surface?

If the masses of two planets doubles and the distance between them also doubles, the force between them would be

Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them

Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them doesn't change, then the force between them is

If your mass remains unchanged while both the mass of Earth and its radius doubles, your weight

Two objects move toward each other due to gravity. As the objects get closer and closer, the acceleration of each

If your mass remained the same while the mass of Earth doubled while staying the same size, your weight would

According to Newton, the closer gravitationally interacting objects are to each other, the

According to Newton, the greater the masses of interacting objects, the

According to Newton, the greater the distance between gravitationally interacting objects, the

If the Earth had twice its present radius and twice its present mass, what would happen to your weight? Explain.

If the mass of Earth somehow increased with no change in radius, your weight would

Newton discovered

If Earth's mass doubled with no change in radius, your weight would

Consider two planets in space that gravitationally attract each other. If the mass of one planet is doubled, and the distance between them doesn't change, then the force between them is

How is stepping off a curb similar to taking a ride aboard the space shuttle?

If the masses of two planets doubles and the distance between reduces by half, the force between them would be

The Earth and the Moon gravitationally attract each other. Does the more massive Earth attract the Moon with a greater force, the same force, or less force than the Moon attracts the Earth? What reasoning guides your answer?

What is the force of gravity on a 500-N woman standing on Earth's surface?

If Earth's mass decreased to one-half its original mass with no change in radius, your weight would