Physical Science Chapter 7
Why do both the sun and moon exert a greater gravitational force on one side of earth than the other?
-Sun is half effective as the as the moon, the sun pulls 180 times harder on earth than the moon, sun pulls almost as hard on the far side of earth as it does on the near side. -Moons force gets weaker with distance, the gravitional force between the earth & moon is stronger on the side of earth nearer to the moon than on the opposite side of the earth.
What is the magnitide of the gravitational force between the earth and a 1-kilogram body?
...
What is the magnitude of gravitational force between two 1-kilogram bodies that are 1 meter apart?
0.0000000000.667 newton
Which pulls with greater force on the earth's oceans, the sun or the moon? Which is more effective in raising rasing tides?
-Sun -Moon
Are all tides greatest at new or full moons
Full moons
how does the force of gravity between two bodies change when the distance between them is doubled?
Gravity gets weaker
Dark Matter
Mysterious matter diffrent than known matter can't be with gravitational effects.
Distinguish the difference between Neap and Spring tides
NEAP- High or low tides that occur when the sun, moon and earth are lined up and the tides collide Spring-Tide that occur when the moon is midway between new and full moon.
What do we call the grivitational force between the earth and your body?
Regardless of masses & distance between them, the gravitational force will stay the same value of G
Spring tides
Tides that occur when the moon is midway between new and full, in either direction.
whats the diff between big bang and big crunch
big bang- the explosion of space itself big crunch- universe may contract and fall back into a single unity.
Law if universal gravitation
everybody in the universe attracting force F=G m1,m2/d2
What makes earth round?
everything attracts everything else, and all parts of the earth have attracted themselves together as much as they can.
Neap tide
high or low tide that occurs when the sun, earth, and moon are all lined up so that the tides due to the sun and moon coincide, making the high tides higher than average and low tides higher than average.
In figure 7.3, we see that the moon falls around the earth rather than straigth into it. if the tangential velocity were zero, how would the moon move?
if the moon's tangential velocity were 0, it would fall straight down and crash into the earth!
inverse square law
relating the intensity of an effect to the inverse square of the distance Intensity is the same as 1/distance2
Do tides depend more on the strength of gravitational pull or on the difference in strengths? Explain
strengths of gravarional pull
If you pull a blob of jell-O equally on all parts, it will keep its shape as it moves. But if you pull harder on one end than the other, it will strech, How does this relate to tides?
the differences in the pulls on the jello is similar to the differences in pulls on the oceans distort the ocean & produce tides.
what happens if the mass of one body is doubled & the other is trippled
Double x triple =six. so the force is six times as much
How bright would the sun look if you were on a planet twice as close to the sun?
Four times brighter
How does the brightness of light change when a point soure of light is brought twice as far away?
If its twice as far the light will be twice as bright.
When G was first measured, the experiment was called the "weighing the earth experiment". Why?
Newton's formula gives the mass of the entire world, with all its oceans, mountains, and inner parts yet to be discovered.
At what distance from earth is the gravitational force on an object zero?
No matter how far away, the earth's gravitational force approaches, but never reaches zero.
We know that both the moon and the sun produce our ocean tides. And we know the moon plays the greater role because it is closer. Does its closeness mean it pulls the oceans with more gravitational force than the sun?
No the sun's pull is much stronger. But tides are not caused by gravitational pulls. Tides are caused by differences in pulls across a body. Differences in pulls, not pulling strength, is the key to tides
consider an apple at the top of a tree. The apple is pulled by earths gravity with a force of 1 N. if the tree were twice as as tall would the force of gravity be only 1/4 as strong? Defend your answer?
No, because twice -as-tall apple tree is not twice as far from the earths center.
light from the sun, like gravity, obeys the inverse-square law. If you were on a planet twice asfar from the sun, how bright would the sun look?
One-quarter as bright
What does it mean to say something moving in a curve has tangential velocity?
That the velocity is parallel to earths surface. Example if an apple from a tree at rest, it falls straight downward. But if it falls from a moving tree, it falls in a curved path.
Universal constant of gravitation
The constant of proportionality in Newton's law of gravitation, usually denoted "G".
What happens if the masses of both bodies are doubled?
The force is 4 times as much
State Newton's law of gravitation in words. Then do the same with one equation
The force is inversely proportional to the square of the distance separating them, force- mass1 x mass2/distance2
What happens if instead the mass of the other body is doubled?
The force is is still doubled, for it doesn't make any difference which mass doubles which mass doubles .(2 x 1=1 x 2)
what connection did Newton make between the falling apple and the moon?
The force pulling on the apple is the same force that pulls on the moon.
Big Bang
The primordial explosion of space at the beginning of time.
According to the equation for gravity, what happens to the force between 2 bodies if the mass of one body is doubled?
When one mass is doubled, the force between them doubles.
If your mass increases, does your weight increase also?
Yes, in direct proportion. That is, if you mass, your weight also doubles.
If the moon didn't exist, would the earth still have ocean tides? If so, how often?
Yes, the earth's tides would be due only to the sun. They'd occur twice per day (every 12 hours instead of evey 12.4 hours) due to the Earth's daily rotation
What value will result if you let your mass be m1, the mass of the earth m2, and d the earth's radius, in the equation for gravity?
Your Weight
In what sense does the moon "fall"?
the moons tangential velocity keeps it ciontinually falling around the earth instead of directly into it.
How does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away?
the paint would be spread twice as thick
tangential velocity
velocity that is parallel (tangent) to a curved path.
How much does the force of gravity change between the earth and a receding rocket when the distance between them is doubled? tripled? ten times as much?
when doubled 1/4, when trippled 1/3, ten times as much 1/100
Do tides occur in molten interior of earth for the same reason that tides occur in oceans?
yes but earth tides are much smaller
