Is gravity a centripetal force?

Question

so...um...yea....is it a centripetal force?

Answer 1

Gravity is a central force, which means that gravity acts between the centers of mass of objects. The gravitational force between me and the earth acts between my center of mass and the earth's center of mass.

A centripital force is not an actual force. In physics, it is called a pseudoforce, simply the reaction of objects (per 3rd Law of Newton) to the force that pushes them away from the center of their revolution (the centrifugal force). But gravity is an acutal force, actually one of the four fundamental forces in nature. So, gravity is not a centripital "force", rather, it is a true force. And, after all, the force of gravity would pull us toward our earth in the same way whether it was rotating or not. (And artificial gravity in spaceships like the ISS is actually a centrigufal force.)

Answer 2

That's not how it works. Without going into a great deal of detail, let me just say that the presence of an atmosphere, has nothing to do with gravitational effects, whether they be mass or acceleration produced. The reason astronauts "float around" is because there is not gravity, it has nothing to do with the atmosphere. CentriPETAL and CentriFUGAL forces are related to each other in the following way. "petal" is the force required to keep an object moving along a curved path, "fugal" is the force induced upon the moving object as result of this forced trajectory. So in your example, CENTRIFUGAL force is the force that will simulate gravity on the inside of a rotating cylinder, tube, or whatever else you choose to spin and PULL the astronauts toward the bottom. This may be a little bit too much, but take a look at the referenced link, particularly the picture and you will see why, how and under what conditions this force is created in a spinning cylinder. The last thought I will leave you with... According to relativity, gravity from mass and gravity induced by acceleration is INDISTIGUISHABLE by the individuals in the given referential frame. Said more simply, the astronauts would not be able to tell, simply by feel, whether they were in a spinning tube, an accelerating space craft, or under the gravitational influence of a massive body. Enjoy the study. It's fun stuff! :) T

Answer 3

First off a centripetal force in not imaginary, the centerfugal force is though. And gravity can be the centripetal force.

Answer 4

Hope your homework is going well.

Centripetal forces are "inward acting" forces. If you get far enough from the earth, and consider something such as a satellite orbiting around the earth, would you consider that earth's gravity is an "inward acting" force? Probably.

On the surface of the earth, or in your bedroom, could you consider gravity to be an inward acting force? Probably not. It acts downward, and its influence is considered uniform in such places.

Answer 5

If you mean does the earth have gravity because it spins, the answer is no. This is a common misconception. The earth would still have gravity if it did not spin. Large masses, like the earth, simply attract things. Wiki Newton's law of universal gravitation.

Answer 6

in some cases yes. this same force prevents the earth from escaping the sun's gravity

Answer 7

No. It's the attraction of massive bodies (i.e. bodies with mass) or a distortion in space depending on what theory you lean towards.

Answer 8

It can be (for an object in orbit), but it doesn't have to be.

Answer 9

No.