Determine the balls mass from force by gravity

[nickb145]

Homework Statement

Two identical balls, their centers 24.0cm apart, experience a mutual gravitational force of 5.3×10−6N .Find the ball's mass

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Homework Equations

F=Gm1m2/r^2

Isn't this just backwards?

5.3x10^-6=(6.67x10^-11)(m^2)/24^2

6765.28kg? that wasn't right
i thought it may be in g to i made it to 6.67. still not right
Does the radius need to be in cm or m?

The Attempt at a Solution

i tried it out by using the gravitational force equation

 

[gneill]

You chose the correct Relevant equation, for which the constant must be G, not g.

Make sure that your quantities have units that agree. What are the units of G? How about r?

 

[nickb145]

Sorry, but yes it should be G. I did mean G though

the units are Newtons and Centimeters