# I cant figure out the answer to this question

1. Feb 6, 2007

### aparra2

Does gravitational acceleration g vary with distance, mass, size of the object?

2. Feb 6, 2007

### cristo

Staff Emeritus
What do you think? What do you mean by "distance of the object"?

3. Feb 6, 2007

### aparra2

I think that acceleration has nothing to do wit mass but i has to do with distance and time because g is found by dividing 2d/t squared. BUt size doesnt matter and mass only matter when talking about force right?

4. Feb 6, 2007

### hover

Are you sure that mass has nothing to do with acceleration?? Double check your work.

Last edited: Feb 6, 2007
5. Feb 6, 2007

### aparra2

ok maybe i was wrong mass does have to do with the acceleration bc acelleration is the force divided by the mass but.But does the size of the size of the object dosent matter. My reasoning tell me that, lets say u have a cube of 10mx20x30 meters of aluminum and also a ball of steel the size of a ping pong ball they both have the same acceleration of gravity when they are both subjected to free fall test

6. Feb 6, 2007

### hover

For an object accelerating towards a mass, no mass doesn't matter (i think i read your question wrong sorry). Any mass, no matter how big or small will always accelerate at the same speed.

The acceleration of that object depends on the mass it is accelerating to and how far it is from the mass' center. There is an equation to figure out how fast an object accelerates near a mass. See if you can figure it out. Hint, it is related to G*m*m/r^2.

Last edited: Feb 6, 2007
7. Feb 7, 2007

### cristo

Staff Emeritus
You are correct that the acceleration of an object does not depend on mass or size (for the latter, neglecting air resistance).

The actual value of g does decrease as we move further up away from the earth's surface. However, this decrease is negligible if the distance moved up is small in comparison with the earth's surface.