Can you tell me about earth's gravity please...

Question

can you tell me all about earth's gravity?

Answer 1

Gravity is the pull between 2 objects.  It is determined by the mass of the objects.  It pulls other objects that are within the scope of its gravity.  It holds us on the Earth and keeps our atmosphere here.  The sun's gravity holds Earth and the other planets in their orbits.  The Earth's gravity holds the Moon in its orbit.  An object has to be orbiting at the right distance and speed to not have its orbit decay, and crash into the object it is orbiting.

Answer 2

Can you be more specific?

Answer 3

A few things I'd like to add to/edit on part of  the first answerer's answer:

"Earth pulls all objects toward it at 9.8 m/sec."

It's actually an acceleration, so it should read 9.8 meters per second squared.  (minor detail)  An object that has been falling for two seconds will be falling at a much faster speed than one falling for only one second...  96.04 meters per second vs. 9.8 meters per second... But "terminal velocity" also comes into play, where an object will finally reach a maximum speed, and stop accelerating.  And obviously, this isn't true for "ALL" objects.  Helium, clearly does not fall to the earth at all (hydrogen too, due to their incredibly small mass, the denser "air" falls to earth, and these elements appear to "float away"  into the sky.  Also, paper, leaves, and feathers will not fall at this acceleration, due to air resistence.  But, if you were able to eliminate air resistence, i.e. lay the peice of paper on top of a physics textbook, and drop them both, the single sheet will fall at the same acceleration as the book, beacuse the air resistence is negated.

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Gravity is influenced by mass AND distance.  It weakens with objects of smaller mass, as well as with object of larger mass, if they are far enough apart.  This is part of the reason why the moon doesn't "fall into the earth,"   it's velocity is another factor.

The source listed below is a fun site (if you're into the mathematics of it) that allows you to enter two objects mass and the distance between them to see the gravitational force they have between each other.

Answer 4

Einstein showed that gravity was not a magical "pulling" force from a distance like Newton had thought. There is a two way interplay between matter and space-time. Matter warps space-time and warped space-time can affect the paths of least energy of other moving objects (even photons!). The amount of effect depends on the relative size of the "smaller" moving objects to  the relative size of the "larger" object's space-time warpature. This means that gravity is really a concrete space-time "push" not a magical, mutual "pull from a distance". The Earth's space-time warpature itself pushes the moon around it, and pushes apples toward its center. Roughly, like a taut trampoline would push a rolling marble toward the bigger indentation made by a very heavy cannon ball at its center.

Answer 5

What do you need to know?  gravity is a force that affects all objects with mass.  Even you have gravity.  Earth's effect on you is the combined force of your gravity pulling on the Earth and the Earth pulling on you.  Earth pulls all objects toward it at 9.8 m/sec. The moon also has gravity that affects Earth.  The tides are caused by the Moons pull on Earth.  Earths gravity combined with the moons gravity cause both objects to dance thru the solar system spinning on the center of thier combined masses and distance apart.  And it goes on and on and on.