Can someone help me, why is this not working?
ClearAll["Global`*"]
EE = 10000;
\[Alpha] = 1;
\[Beta] = 2500000;
\[Kappa] = 1/10000;
H = 5;
S0 = 1;
eq1 = EE Derivative[0, 2][u][t, x] + \[Alpha] Derivative[1, 0][p][t, x]
eq2 = (1/\[Beta]) Derivative[1, 0][p][t,
x] - \[Alpha] Derivative[1, 1][u][t,
x] - \[Kappa] Derivative[0, 2][p][t, x]
eq3 = u[t, 0]
eq4 = p[t, 2 H]
eq5 = p[t, 0]
eq6 = p[0, x]
eq7 = u[0, x]
tf = 1000;
s = NDSolve[{eq1 == NeumannValue[S0, x == 2 H], eq2 == 0, eq3 == 0,
eq4 == 0, eq5 == 0, eq6 == 0, eq7 == 0}, {u[t, x], p[t, x]}, {t, 0,
tf}, {x, 0, 2 H},
Method -> {"PDEDiscretization" -> {"MethodOfLines",
"TemporalVariable" -> t}}]
Plot3D[Evaluate[p[t, x] /. s], {t, 0, tf}, {x, 0, 2 H} ,
PlotRange -> All]
Plot3D[Evaluate[u[t, x] /. s], {t, 0, tf}, {x, 0, 2 H} ,
PlotRange -> All]