# CHAPTER 9 (PHYSICS)

Flashcard maker : Evie Nicholson
What happens to the force of distraction between two planets when the distance between them is doubled?
The force decreases to one quarter
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
Greater than your normal weight at rest
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
Less than your normal weight at rest
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?
The elevator moves downward while slowing in speed
If you are standing on a scale in an elevator, what exactly does the scale measure?
The force you exert on the scale
How does the gravity in the space shuttle compare with the gravity on Earths surface?
The gravity in the space shuttle is approximately equal to the gravity on the surface of the Earth
Why does the gravity in the space shuttle compare with the gravity on Earth the way it does?
The space shuttle is about the same distance from the center of the Earth than from the surface of the Earth
Why do the astronauts in the space shuttle float around?
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.
Each day
There are two high tides and two low tides
THe moons gravitational pull is
Strongest on the side of Earth closest to the moon
Approximately how much time passes between low and high tide?
6 hours
A high tide can occur
When the moon is high overhead
If there were no moon would there still be tides on earth?
Yes because the suns gravity still has an influence
How do the high tides during a full moon compare to high tides during a new moon?
The high tides during a full moon are roughly the same as the high tides during the new moon
Which of the following lists correctly gives in increasing order, the height of the high tides that occur during particular lunar phases?
(First quarter, third quarter) (New,full)
Einstein’s theory of gravitation, compared with Newtons
Eliminates the role of force
From the viewpoint of an observer in the orbiting rocket, what happens to time on the other rocket as it falls toward the event horizon of the black hole?
Time runs increasingly slower as the rocket approaches the black hole
As the failing rocket plunges toward the event horizon, an observer in the orbiting rocket would see that the falling rocket
Slows down as it approaches the event horizon and never actually crosses the event horizon
From Part B, you know that from afar we’ll never see the in-failing rocket cross the event horizon, yet it will still eventually disappear from view. Why?
Its light will become so redshifted that it will be undetectable
If you were inside the rocket that falls toward the event horizon, you would notice your own clock to be running
At a constant normal rate as you approach the event horizon
If you were inside the rocket that falls toward the event horizon, from your own viewpoint you would
Accelerate as you fall and cross the event horizon completely unhindered
Where does an object on an elliptical orbit experience the greatest acceleration?
Where spacetime has the most curvature
Imagine that the sun could be turned into a black hole without changing its mass. How would Earths orbit change?
Earths orbit would not change
Imagine that the sun gained mass without changing its radius. How would the structure of spacetime change at the distance of Earths orbit?
Spacetime would become more curved at Earths orbit
Black holes are essentially
Collapsed stars
Is gravitational force acting on a person who falls off a cliff?
Yes
Is gravitational force acting on an astronaut inside an orbiting space shuttle?
Yes
Newton discovered
That gravity is universal
According to Newton, doubling the distance between to interacting objects
Divides by 4 the gravitational force between them
What is the force of gravity on a 500 newton woman standing on the earths surface?
500 N
If the mass of the earth somehow increased with no change in radius, your weight would
Increase also
Inside a freely falling elevator, there would be no
Apparent weight for you
The earths gravitational field extends
Both inside and outside the earth and throughout the entire universe
A black hole
Simply the remains of a giant star that has undergone gravitational collapse
An astroid exerts a 360 N gravitational force on a nearby spacecraft. This force is directed
Toward the astroid
An astroid exerts a 360 N gravitational force on a nearby force on a nearby spacecraft. If the spacecraft moves to a position three times as far from the center of the asteroid, the forces will be
40 N
An object is placed exactly halfway between the Earth and moon. The object will fall toward the
Earth
The amount of gravitational force that acts on the space shuttle while in orbit is
Almost as much as the shuttles weight on the earths surface
A weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above the Earths surface. How much would she weight there?
100 N
Two objects move toward each other because of gravity. As the objects get closer and close, the force between them
Decreases, then increases
The force of gravity acts on all apples on an apple tree. Some apples are twice as far from the ground as others. These twice as high apples, for the same mass have
Practically the same weight
Half way to the center of a completely hollow planet with a thin uniform shell, your weight would be
Zero
Inside a freely falling runaway elevator, your
Apparent weight is zero
No force due to earths gravity is acting on the astronauts inside the orbiting space shuttle. This statement is
Always false
The factor most directly responsible for making a black hole invisible is its
Surface escape velocity
When a star collapses to form a black hole, its mass
Remains the same
How far must one travel to get away from the Earths gravitational field?
Forget it, you cant travel far enough
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 planets surface, inhabitants, fins that the gravitational field inside the planet is
Non zero, directed toward the spaceship
Which pulls on the oceans of the Earth with the greater force?
The Sun
Which is most responsible for the ocean tides?
The moon
The main reason ocean tides exist is that the pull of the moon
Is greater on oceans closer to the moon and less on oceans farther from the moon
If the earths mass decreased to one half its original mass with no change in radius, then your weight would
Decrease to one half your original weight
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?
Both the force on A and B