function [dpdt] = test8(t, p)

M1 = 30;
M2 = 10;
k1 = 200;
k2 = 300;
B1 = 30;
B2 = 10;

dpdt = [
    p(2)
    (1/M1)*(-k1*p(1)-B1*(p(4)-p(2)))
    p(4)
    (1/M2)*(B1*(p(4)-p(2))+k2*p(3)+B2*p(4))
];

end