Physics Chapter 9

What is the magnitude of Earth's gravitational force on a 1-kg body at Earth's surface?

10 N

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

decrease.

When the distance between two stars decreases by one-third, the force between them

increases to nine times as much.

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

increases.

The event horizon of a black hole is best described as

the boarder surrounding a black hole where the force of gravity is so great that even light can not escape

One side of the Moon continually facing Earth is

tidal lock.

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

6.67 × 10 -11 N

Calculate the force of gravity on the 1-kg mass if it were 6.4×106 m above Earth's surface (that is, if it were two Earth radii from Earth's center).

F = 2.4 N

Which is most responsible for Earth's ocean tides?

Moon

Which has the higher tides: spring tides or neap tides? Why?

Spring tides are higher, because the tides from the Moon and Sun add together.

Describe how the gravitational forces from the Sun and the Moon compare from one side of Earth to the other.

The Sun exerts a stronger force on the side of Earth nearest the Sun, and the Moon exerts a stronger force on the side nearest the Moon.

How does the force of gravity between two bodies change when the distance between them is doubled?

The force decreases to ¼ of its initial value.

What happens to the force of attraction between two planets when the masses of both are doubled?

The force quadruples.

A very massive object A and a less massive object B move toward each other under the influence of gravity. Which force, if either, is greater?

both forces are the same.

The force of Earth's gravity on a capsule in space increases as it comes closer. When the capsule moves to half its distance, the force toward Earth is then

four times greater.

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

greater the gravitational force between them.

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

increase also.

The main reason ocean tides exist is that Moon's pull is stronger

on water closer to it than on water farther away.

The force of Earth's gravity on a capsule in space will lessen as it moves farther away. If the capsule moves to twice its distance, the force toward Earth becomes

one-fourth.

According to Newton, when the distance between two interacting objects doubles, the gravitational force is

one-quarter.

Gravitational lensing

provided validation of Einstein's theory of gravitation, allows us to see an image of an object that is directly behind a massive celestial object, shows us that light can bend around a massive object

Tidal forces in general are the result of

unequal forces acting on different parts of a body.

In Einstein's Theory of gravity

warped space-time affects the motion of objects with mass, the gravitational field is portrayed as a warping of space-time, forces are not used to describe gravity, warped space-time affects the motion of light