A thin string of length L = 3m is pinned at the two ends. Based
on the material linear density ρ and on the traction force T, it
can be assumed that √ T/ρ = 2 m/s. The string is initially straight
when, at time t = 0, it is tapped in two narrow intervals (1 − 1/8,
1 + 1/8) and (2 − 1/8, 2 + 1/8) with opposite velocities +1m/s and
−1m/s, respectively. i) Derive the field equation...