Spring-Mass System Matrix

  • #1

Main Question or Discussion Point

The differential equation that model an undamped system of 3 masses and 4 springs with external forces acting on each of the three masses is


a)express the system using matrix notation x'=Kx+g(t) for the state vector x=(x1,x2,x3)T. Identify the matrix K and the input g(t).

b) Give conditions m1, m2, m3, k1, k2, k3, k4 under which K is a symmetric matrix.

I am pretty sure I have gotten the first part but I am having trouble even figuring out what the second part means. When I created my matrix K it seems like it is already a symmetric matrix. Any help would be great.

Answers and Replies

  • #2
Science Advisor
Homework Helper
I don't undestand part (b) either.

The equations you are given will be symmetric for any values of the m's and k's - so what was the question really asking you about :confused: