A mass M₁ = 1.80 kg rests on a horizontal table which has a coefficient of kinetic friction of µ_k = 0.004. This mass is connected to a horizontally mounted spring which has a spring constant of k = 400 N/m. The spring is initially at its unstretched, equilibrium length. A second mass M₂ = 2.20 kg is connected to M₁ by a massless high tensile wire that passes over a frictionless, massless pulley.

 

When M₂ is released the system oscillates in simple harmonic motion.