Trying to figure out gravitational attraction between two objects.

AI Thread Summary
The discussion focuses on calculating the gravitational attraction between two objects using Newton's Law of Universal Gravity. Participants clarify that the force of attraction is proportional to the product of the masses and inversely proportional to the square of the distance between them. The formula provided is G x M1 x M2 / R^2, where G is the gravitational constant. A fifth grader seeks help with the calculation, expressing difficulty due to a lack of a suitable calculator. The expected result is a very small force, highlighting the minimal gravitational attraction between the specified masses at the given distance.
LuigiHomer
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Trying to figure out the gravitational attraction between two objects using Newton's Law of Universal Gravity.Need to figure out what the force is.Here is a model.If anything is in ordinary parentheses then it is an exponent.

----------------------G
--------____________|_____________400x300
F1=F2=[6.673x10(-11)N m(2) kg (-2)] -----
-------------------------------------2,000(2)






Force is proportional to the product of the two masses{120,000}and inversely proportional to square of distance between two point masses.{4,000,000}




Please help me figure out what F1 is,since F1 is equal to F2.

-LH
 
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First thing you must do is ensure all your numbers are in the right units: kilograms & metres (since those are the units that G is in). I don't know what units your numnber are in now.

F - the force between them - will be equal to your formula there.
 
Okay.The two point masses are in KG.The distance is in metres.G is in Newtons.
 
So, what answer did you get?

The formula you have listed will calculate "the force of attraction between two bodies". One force, not two. Not sure where the F1=F2= came from.
 
I can't figure it out.Kind of new to the concept of using Newton's laws.Kind of new to physics.
 
I would think F1 is force felt by object #1 and F2 is the force felt by object #2, and they are equal in magnitude, while opposite in direction.

Simply multiply and divide and you are done.

G x M1 X M2 / (R x R) = F1 = F2

From your post we have:

M1 = 400 KG
M2 = 300 KG
R = 2000 M

And we know G.

So, just do the math! There's no physics left to figure out.
 
I don't have a calculator that can even REGISTER Newtons,and our teacher took it away.:(What a meanie.
 
My sister THINKS it is 0.030.
 
Do you guys have a suggestion
for a good, reliable computer calculator for free that can do what Molinaro said to do?
 
  • #10
@ DaveC,It is that they BOTH exert gravitational force.F1 is equal to F2,which is the other force.
 
  • #11
LuigiHomer said:
Do you guys have a suggestion
for a good, reliable computer calculator for free that can do what Molinaro said to do?

> START > PROGRAMS > ACCESSORIES > CALCULATOR

then menu > VIEW > SCIENTIFIC
 
  • #12
My sister didn't incorporate G.My head hurts.I'm only in 5th grade,you know.
 
  • #13
I think it's 0.6.Please help me.More.
 
  • #14
LuigiHomer said:
I don't have a calculator that can even REGISTER Newtons,and our teacher took it away.:(What a meanie.
You don't need a calculator that registers' Newtons...
You're just doing math.
 
  • #15
LuigiHomer said:
@ DaveC,It is that they BOTH exert gravitational force.F1 is equal to F2,which is the other force.

They do both exert a force. That formula will calculate the entire forfce between the two masses.
 
  • #16
DaveC426913 said:
You don't need a calculator that registers' Newtons...
You're just doing math.

Once again,I AM A FIFTH GRADER!
 
  • #17
LuigiHomer said:
Once again,I AM A FIFTH GRADER!
I'm sorry, I missed that.

Have you learned exponents?
6.67x10^-11 is equal to .0000000000667

So:

F = (.0000000000667)*400*300 / (2000^2)

Masses of 300-400kg that a distance of 2km have an extremely small force of attraction.
Your answer should be a very, very small number - about 11 zeros.
 
  • #18
LuigiHomer said:
I'm only in 5th grade,you know.

No, we didn't know that, until you mentioned it in this post. :rolleyes:
 
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