m1 = 50;
m2 = 300;
k12 = 20000;
k01 = 200000;
v12 = [-0.1 0 0.1 0.2];
Fd = [-0.1*1500 0 0.1*4000 0.1*4000+0.1*2000];

M = [m1 0;0 m2];
K = [k01+k12 -k12
     -k12    k12];
F = [k01; 0];
invM = inv(M);