Suppose a mass m is attached to two springs with spring constants k1 and k2 and lengths l1 and l2 in series. The mass moves horizontally.
The motion equation of the mass is represented by:
m(d^2x/dt^2) = -k2(x - xc - l2)....(ii)
1. (8 points) Find the equilibrium position of the mass m using (i) and (ii).
2. (6 points) Assume that k2 = k1 = k and l2 = l1 = l. Derive that m(d^2x/dt^2) = -kx from Problem 1.
3. (12 points) Solve the differential equation in Problem 2 and show that the mass executes simple harmonic motion about its equilibrium position. That is, show that the solution form is x(t) = Asin(wt + φ) + xE.
4. (5 points) Find the frequency w and period T.
5. (20 points) Let m = 1, k = 1, and l = 1. When the initial conditions x(0) = 2 and dx/dt(0) = 4 are given, find the equation of the energy, graph the energy curve and the corresponding phase plane. Check the stability of the equilibrium position based on the linearized stability analysis.