Acceleration due to gravity in a galaxy?

In summary, to determine the acceleration due to gravity at the periphery of a galaxy, you need to know the distance from the galaxy center, the total mass of the galaxy within that radius, and the gravitational constant. Using this information and Newton's law of gravity, you can calculate the acceleration yourself. Based on estimates of the distance and mass of our galaxy, the acceleration at the periphery is approximately 0.4 nanometers per second squared. The equation for this calculation is GM/r^2.
  • #1
Bjarne
344
0
How strong is acceleration due to gravity ?
For example at the periphery at a galaxy ?
 
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  • #4
To determine the acceleration due to gravity at the periphery of a galaxy, you need to know three numbers. The first is the distance from the galaxy centre where your acceleration is to be calculated (the radius). The second is the total mass of the galaxy contained with that radius. The third is the gravitational constant, G.

Lastly, you will need to learn about Newton's law of gravity (the wikipedia article is suffucient). With the above three numbers, some knowledge of how gravity works and a little bit of calculating, you should be able to work the numbers out yourself.
 
  • #5
Bjarne said:
How strong is acceleration due to gravity ?
For example at the periphery at a galaxy ?

Put this into google "G*(mass of sun)/(1 AU)^2"
without the quotes
The google calculator will tell you the accel due to sun's mass at the Earth's usual distance of 1 AU.The distance from center to apparent edge is sometimes estimated
about 15,000 parsecs. The mass of our galaxy within that radius has been put at 700 billion solar masses. Try this in the google search window, without the quotes:

"G*(700*10^9 mass of sun)/(15 kpc)^2"

I think you will get around 0.4 nanometer per second per second.
 
Last edited:
  • #6
Thank's

PS..
1.) I thought the equation was more complicated (Einstein’s Field Equation). But I assume GM/r^2 can be used as a rough estimation (?).
2.) I thought there are “only" 200 stars” in a typical galaxy (not 700 ?)
3.) 15,000 parsecs = 4,62e20 Meter (50.000 LY )

700e9*2e30*6,67E-11/4,62e20^2= 4,37e-10 M^2
 

What is acceleration due to gravity in a galaxy?

Acceleration due to gravity in a galaxy is a measure of how fast objects within the galaxy are pulled towards its center. It is caused by the mass of the galaxy and can vary depending on the distance from the center and the mass distribution within the galaxy.

How is acceleration due to gravity in a galaxy different from Earth's gravity?

Acceleration due to gravity in a galaxy is different from Earth's gravity because it is not a constant value. Earth's gravity is relatively consistent at 9.8 meters per second squared, while in a galaxy, it can vary greatly depending on the location and mass distribution within the galaxy.

What factors affect acceleration due to gravity in a galaxy?

The main factors that affect acceleration due to gravity in a galaxy are the mass of the galaxy and the distance from its center. The distribution of mass within the galaxy can also play a role in determining the strength of gravity.

How is acceleration due to gravity in a galaxy measured?

Acceleration due to gravity in a galaxy is typically measured using astronomical observations and mathematical calculations. Scientists can observe the movement of objects within a galaxy and use equations, such as Newton's Law of Universal Gravitation, to determine the acceleration due to gravity.

Can acceleration due to gravity in a galaxy change over time?

Yes, acceleration due to gravity in a galaxy can change over time. This is because the mass and distribution of mass within a galaxy can change due to the movement and interactions of stars and other celestial bodies. However, these changes are usually very gradual and may not be noticeable within a human lifetime.

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