What are the components of force in 3D for a pulled atom?

[Gogsey]

This not so much of a homework proble, but something I need to visualize and understand to do a homework problem.

If theeres and atom at x,y,z = 0, and one located at x,y,z, = 1/2 and we pull second atom from its posistion with a force F in anyone of the x,y,z directions, what are the components of the force in the x,y and z directions?

I thought that if you pulled it in any of the directiosn, each coponent would be equal and add to give F. So, 1/3 of the force would be in each of the x,y,z directions no matter if you add a force F in x,y, or z.

I have trouble picturing what's happening in 3D.

 

[cupid.callin]

and we pull second atom from its posistion with a force F in anyone of the x,y,z directions, what are the components of the force in the x,y and z directions?

Well, the component of force will be F in direction you choose to pull it and 0 in rest directions.

I thought that if you pulled it in any of the directiosn, each coponent would be equal and add to give F. So, 1/3 of the force would be in each of the x,y,z directions no matter if you add a force F in x,y, or z.

I really can't understand what you are trying to say

 

[Gogsey]

The picture is a bcc lattice with all the atoms connected to each other.m Now ere onlt consideruing the effects of moving each atom on the centrakl atom. So applying a force in each dimension, and seeing what happens to the atiom in the centre of the cube.

So put a force in the x direction, and see what the restoring force is in x, y and z directions. And we do thies for all 9 atoms including moving the one at the centre of the cude and seeing theeffect on all others.

I guess because of symmetry, there will be zero movement in the y direction, when applyong aforce in the x direction, same for yz and xz combinations. So there should only be a movement in the x direction when there a force along x, and same for yy, and zz.

If we say the atom at the centre is at (0,0,0) and the other ones are are +/-x,+/-y,+/-z, so eight atoms. I was wondering if there woul;d be changes in position to the other atoms in all directions, no matter the direction of the force. But because of symmetry, al lot of these forces will cancel out.