How to solve for mass given gravitational force and radius ?

[scientific_vi]

how to solve for mass given gravitational force and radius ?

Homework Statement

The gravitational force between two identical objects 2.00m apart is 3.50x10^-6N. determine the mass of each object.
the answer should be [458kg]

Homework Equations

i know that Fg= GmM/r^2
so gravitational force is equal to the gravitational constant times mass one and mass two over the radius squared

The Attempt at a Solution

i tried manipulating the formula to solve for the masses
i went
Fgr^2/G=mM

i did (3.50x10^-6N)(2.oo^2m)/(6.67x10^-11)

which does not give me the answer of 458kg
please help!

 

[Villyer]

You calculated Fgr^2/G, which you said was equal to mM.

They didn't ask for mM though, so you haven't finished the problem yet.

 

[scientific_vi]

but mM is the masses though.
so would i need to solve for mass one in order to solve for mass two ?

 

[Villyer]

mM is the product of the masses. You need to find each of them, m and M.

What is the relationship between m and M?

 

[scientific_vi]

mM is the product of the masses. You need to find each of them, m and M.

What is the relationship between m and M?

im not sure on how to solve for each m individually.
am i manipulating the formula incorrectly?

 

[Villyer]

No, it was correct to solve it for mM.

What do they tell you in the problem about the two masses that might help you solve for one?

 

[scientific_vi]

No, it was correct to solve it for mM.

What do they tell you in the problem about the two masses that might help you solve for one?

they are both identical .
haha ohkay so if i calculate one they should both be the same.

 

[Villyer]

Exactly.

Mathematically, m = M.

 

[scientific_vi]

Thanks a million .
i must read the questions more carefully hah.