- #1

harrysawizard

- 4

- 0

## Homework Statement

A cube has an edge length of 2.0m. At each corner there is a different spherical mass. The masses are 1kg, 2kg, 3kg, 4kg, etc. u to 8kg. They Coordinate system: 1kg is at the origin and the 4kg, 2kg, and 8kg masses lie on the positive x, y, and z axis respectively. What is the net gravitational force acting on the 1kg mass? (magnitude and direction)

(I know I don't have an image, but it won't let me insert one and at the point I'm at, I think I'm past needing the image)

## Homework Equations

To find the force each mass is putting on the 1kg mass, I used equation:

F = G m

_{1}m

_{2}/r

^{2}

where G is 6.67 * 10

^{-11}and r is the distance between 2 objects.

I substituted 1 for m

_{1}and 2 for r, coming up with simplified equation:

F = (6.67*10

^{-11}) (m

_{2}) / 4

## The Attempt at a Solution

I used that equation to find the x, y, and z components of every force.

I then added to find [tex]\Sigma[/tex]x, [tex]\Sigma[/tex]y, and [tex]\Sigma[/tex]z.

I got:

[tex]\Sigma[/tex]x = 3.0015 * 10

^{-10}

[tex]\Sigma[/tex]y = 2.668 * 10

^{-10}

[tex]\Sigma[/tex]z = 4.3355 * 10

^{-10}

My question is, what do I do now to find the total magnitude of the force?

Once I get that, how do I find the angle / direction of the force?

If I were to use the 3-d distance equation, how would I find the angle?

I'm completely stuck, so any help is greatly appreciated!

*Thanks so much guys, this is my first day on the site so I don't quite know what I'm doing! (:*

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