A vibrating system has a mass m = 10kg suspended from a spring of modulus k = 2500N/m nd damping amunts to c = 45 Ns/m. Vibration is caused by a harmonic force of F = 180 and frequency 3.5Hz. The initial displacement and velocity of the mass are 15 mm and 5m/s respectively. Determine.
1) Write the equation of motion of the system.
2) Determine the complete solution of the motion of the mass.