Does a planet that doesn't spin, have gravity? Is gravity created simply by mass?

Question

An earthlike planet was discovered, similar in size but doesn't spin yet it is estimated to have 1.5 times our gravity. I thought centrifugal force by spinning created our gravity. Is it simply mass that generates gravity?

Answer 1

The spin of the planet does not influence its gravitational pull on other objects.
The planet’s mass is what determines how strong a planet’s gravity is.
The classical explanation is that mass caused gravity.

Newton’s Law of Universal Gravitation is:
F = G * M * m / r^2
Where G is some constant (its specific value is unimportant in this explanation but it is 6.67 E-11 N m^2 kg^-2), M and m are the masses of the planet and the object which is being attracted to the planet, and r is the radial distance the two objects are apart from each other.
The spin the either object does not come into play here since it is irrelevant in calculating the gravitational force between the objects (F).

An increase in mass (either M and/or m) will cause the force, F, to increase. Likewise, a decrease in the distance between the objects (r) will increase the gravitational attractive force.

In the case of this newly discovered planet, its mass and size (radius) are such that the gravitational acceleration experienced on the surface of the planet is equation to about 1.5 times that of the Earth.

By comparison, on the surface of the Moon, the gravitational acceleration is about 1/6 of that of the Earth due to the smaller mass of the moon.

Answer 2

Yes, gravity is created simply by the mass. Spin has nothing to do with gravity.

But many people are confused because some space station ideas use spinning to make gravity, but that is totally different. In the space station, the people stand INSIDE of it and centrifugal force makes them get pushed to the outside. The outer rim of the wheel shaped station would be the FLOOR. A planet gets gravity only from its giant mass and people are pulled toward the center. They stand on the OUTSIDE of the round planet,

Answer 3

Mass alone creates gravity. However, a planet that spins has less gravity at its equator than at the poles. The number for earth is about ½% less gravity at the equator.

That planet must simply be composed of something more dense than earth.

Answer 4

Gravity: Any two objects in the universe attract each other with a force proportional to their masses and inversely proportional to the square of their distance. We don't know what causes it, all we can do is describe it. specific gravity: The ratio of the density of a material to the density of water. accelerational force? perhaps you mean acceleration due to gravity? (for earth's surface that is 9.8 m/s²). From Newton's F=ma, force causes an acceleration in a mass. In this case, the force of gravity of the earth on an object causes it to accelerate towards the center of the earth, if it is not supported. .

Answer 5

Mass causes gravity. Spinning has nothing to do with it.
We cannot say how big 581 c is. We can only detect its mass by the wobble of its parent star Gliese 581. We don´t yet know if it is a rock or a gas world like Neptune.

Answer 6

Yes, it is simply mass that creates gravity. Centrifugal force is not relevant at all in planetary gravity. It is only relevant in *artificial* gravity in space stations (for example).

Answer 7

Yes, large concentrations of matter produce their own gravity without any movement needed whatsoever. The fact that it doesn't spin yet probably means it has no protective magnetic field surrounding it and that, I might add, is not good....

Answer 8

If you're referring to Gliese 581C, it does rotate. But its rate of rotation is the same as its time for an orbit around its sun, so it simply faces one way to its star. Its like the moon - the moon rotates but in the same time it takes to orbit the earth so it always faces one way to earth. Its called tidal locking, because its the tides of the larger, close object that has slowed the smaller object's rotation to match its year.