Physics Chapter 13
A woman who weighs 600 N at Earth's surface stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much does she weigh?
150 N
If Earth had twice its present mass, but the same radius, what would be the value of g?
19.6 g
Suppose the moon were covered with water and orbited Earth as now it does. In that case how many tidal bulges would the moon have ?
2 tidal bulges
About how many high tides are there normally each day on a typical ocean beach ?
2 tides a day
If the radius of Earth were one half what it is now, and its mass were the same, what would be the value of g ?
4x as much
What defines a neap tide ?
90 degrees between earth ,sun and moon
Does the mass of the moon and earth affect the number of tidal bulges on Earth ?
No it does not affect the position
If the moon had oceans as deep as Earth's , would tides on the moon be about the same height as Earth's tides ?
No way to tell
What defines a spring tide ?
When the sun, Earth , and moon all line up
What is the gravitational field strength at the center of the Earth ?
Zero
What is a black hole ? Why is it black ?
a star that collapsed under gravitational attraction. its black because the escape speed is faster than the speed of light
Are tides more likely to occur on a large planet or a small planet ?
difference of forces are bigger on a bigger planet
What is the primary cause of ocean tides ?
differences in the gravitational pull of the moon on opposite sides of the Earth.
What is the cause of ocean tides ?
differences in the gravitational pull or moon on the opposite side of earth
What do gravitational field lines show ?
direction of an objected object in space
What experiment could you do to see if a gravitational force exists in a region of space ?
drop sometimes in that region of space
What causes a lunar eclipse ?
earth blocks the moon
What is it about the Earth that gives it a gravitational field ?
earth's mass
What is the factor most directly responsible for making a black hole invisible ?
escape velocity
According to Newton's laws, a rock and a pebble will fail with the same acceleration in a gravitational field even though the gravitational force on each is different .
force to mass ratio is the sane acceleration
When properties of space are altered in such a way that a mass in that space experiences a force, what kind of field is present ?
gravitational field
Compare the gravitational field on the surface of Earth to the gravitational field well below Earth's surface.
gravity below is less than on surface
If you were to weigh yourself in a elevator that is accelerating upward, would your weight be greater or less than normal ?
greater than the bathroom scale and floor, would push harder against your feet
During an eclipse of the sun, when the moon comes between the sun and Earth, how are ocean tides affected ?
high tide higher and lower tide (spring tide)
In the real world, is the force of gravity on you greater when you are standing on the earth's surface, on a platform above the surface, or in a hole just beneath the surface ?
hole just beneath because you are closer to Earth's center
Does a skydiver jumping from a plane fall in the direction of the Earth's gravitational field, or in a direction opposite that field ?
in the direction of earth's gravity
If Earth had its present mass but twice the radius, what would happen to the acceleration due to gravity ?
increased by 1/4
Gravitation weakens as the inverse square of distance, while tidal gravity weakens with what mathematical relationship ?
inverse cubed distance
When a star collapses to form a black hole, what happens to its mass ?
it stays the same
If you drop a stone into a hole drilled all the way to the other side of Earth, describe the motion of the stone. Where will it be moving fastest ?
it will start slowly and velocity increases acceleration will be the greatest
Suppose the moon had twice its present mass and still orbited Earth at the same distance. In what case what would happen to ocean tides ? Would the tidal bulge facing away from the moon get smaller ?
it would be bigger
When Earth's shadow falls on the moon, what kind of eclipse occurs ?
lunar eclipse
The value of the acceleration due gravity, g, is dependent upon what variables ?
mass and radius
If the sun were to collapse to form a black hole , what would happen to earth ?
nothing it would still continue to orbit
There are two main processes going on in the sun that keep the sun in existence and shining. What are these processes ?
nuclear fusion and gravitational attraction
What causes solar eclipse ?
produced when the moon is directly between the sun and earth
What causes Earth tides, in which the solid surface of Earth rises and falls ?
pulls on one side more than the other
What variables determine the acceleration due to gravity ?
radius and mass
When the moon's shadow falls on Earth, what kind of eclipse occurs ?
solar eclipse
which pulls harder on Earth's ocean , the sun or the moon ?
sun
Does the earth, the moon, or the sun produce a greater tidal effect on you right now ? Why ?
the earth because were closer to it
If the radius of the earth decreased, with no charge in mass, what would happen to your weight ?
weight increase
If the mass of the earth increased, with no change in radius , what would happen to your weight ?
your weight would increase