Shows a mass spring system, which is constrained to move only in the horizontal direction. 

The specifications of the system are: 

the mass m = 2 kg 

the spring stiffness k = 1974 n/m 

initially the mass is at rest, the mass then undergoes, the force distribution of a series of steps, as described by the force-time graph presented as figure q2(b). 

Using the phase-plane method to determine; 

a) the response of the mass for the first 120 ms 

b) the displacement and velocity when t = 120 ms.

+F x+ m = 2 kg k= 1974 N/m Figure Q2a F/N 100 60 20 t/ ms 40 40 40 Not to scale Figure Q2b