Linear Algebra - Hooke's Law Problem

[YoshiMoshi]

Homework Statement

For the system of springs

a) Assemble the stiffness matrix K and the force-displacement relations, K*u = f
b) Find the L*D*L^T factorization of K. Use Matlab to solve
c) Use the boundary conditions and applied forces to find the displacements

Homework Equations

The Attempt at a Solution

I'm getting stuck on part c

My confusion lies in why is F = <10 10 10>^T? I don't see were these 10 values came from.

Thanks for any help!

 

[vela]

Looks like a mistake since gravity isn't involved in this problem.

 

[YoshiMoshi]

I think you might be right. I don't see how gravity is involved either.