chapter 9 1310 holtz
What is the magnitude of Earth's gravitational force on a 1-kg body at Earth's surface?
10 N
A weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much is her weight there?
100 N
Calculate the force of gravity between Earth (mass = 6.0×1024kg) and the Sun (mass = 2.0×1030kg ). The average Earth-Sun distance is 1.5×1011m .
3.6 x 10^22
An 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
40 N
What is the force of gravity on a 500-N woman standing on Earth's surface?
500 N
What is the magnitude of the gravitational force between two 1-kg bodies that are 1 m apart?
6.67 x 10^-11
Earth's gravitational field is strongest at _______.
Earth's surface
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 = G m₁1m₂/d ² = 6.67x 10 −¹¹ N x m² /kg² x (1kg )(6 x 10²⁴ kg )/[2(6.4 x 10⁶m)]² = 2.5N 2.4 N ???
When a star collapses to form a black hole, its mass
remains the same
If Earth's radius somehow increased with no change in mass, your weight would
decrease
If Earth's radius somehow increased with no change in mass, your weight would
decrease.
On each given day and location, tides rise and fall at
different times
Einstein's theory of gravitation, compared with Newton's, _______.
eliminates the role of force
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
Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them
increases
When the distance between two stars decreases by one-third, the force between them
increases to nine times as much.
What happens to the strength of the gravitational field at the surface of a star that shrinks?
it increases
Why is a black hole invisible?
the escape velocity of the black hole is greater than the speed of light
How does the force of gravity between two bodies change when the distance between them is doubled?
the force decreases to 1/4 of its initial value
A black hole is
the remains of a giant star that has undergone gravitational collapse
Which two factors mainly affect ocean tides on Earth?
the sun and the moon
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?
they are the same
One side of the Moon continually facing Earth is
tidal lock
An asteroid exerts a 360-N gravitational force on a nearby spacecraft. The 360-N force on the spacecraft is directed
toward the asteroid
Tidal forces in general are the result of
unequal forces acting on different parts of a body
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.
Which is most responsible for Earth's ocean tides?
moon
Is there change in the force of gravity between two objects when their masses are doubled and the distance between them is also doubled?
no
Two planets in space gravitationally attract each other. If both the masses and distances are doubled, the force between them is
none of the above (the same as before)
The main reason ocean tides exist is that Moon's pull is stronger
on water closer to it than on water farther away.
Which rocket would require more fuel?
one going from Earth to the Moon
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.
The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground as others. For the same mass these twice-as-high apples have
practically the same weight
Why are all tides greatest at the time of a full Moon or new Moon?
At full Moon and new Moon, the tides from the Moon and the Sun add because they are in line with Earth.
In what sense does the Moon "fall"?
It falls away from the straight path that it would follow if there were no forces acting on it.
If Earth shrank, but there was no change in its mass, then what would happen to your weight at the surface?
It would increase.
The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much because
Jupiter's radius is about 10 times Earth's radius
Tides caused mainly by the Moon occur in Earth's
atmosphere, interior, oceans (all)
