Hi Guys, trying to solve three ODE's below and getting the same "non numerical value for a derivative at t==0" error, can't see where i'm going wrong! Please help!
With[{m = 1, M = 1, l = 1, L = 1, g = 9.81, A = 0.01, w = 1000,
yO = 0.1},
sol = NDSolve[{m l \[Theta]''[t] + M L \[Theta]''[t] +
m A w^2 Sin[\[Theta][t]] Cos[w t] - m y''[t] Sin[\[Theta][t]] +
M L \[Phi]''[t] Cos[\[Theta][t] - \[Phi][t]] +
M L \[Phi]'[t]^2 Sin[\[Theta][t] - \[Phi][t]] -
m y''[t] Sin[\[Theta][t]] -
m y'[t] \[Theta]'[t] Cos[\[Theta][t]] +
M A w^2 Sin[\[Theta][t]] Cos[w t] +
M y'[t] \[Theta]'[t] Cos[\[Theta][t]] +
M L \[Theta]'[t] \[Phi]'[t] Sin[\[Theta][t] - \[Phi][t]] -
m g Sin[\[Theta][t]] - M g Sin[\[Theta][t]] == 0 ,
M L \[Phi]''[t] +
M l \[Theta]''[t] Cos[\[Theta][t] - \[Phi][t]] -
M l \[Theta]'[t]^2 Sin[\[Theta][t] - \[Phi][t]] -
M y''[t] Sin[\[Phi][t]] + M A w^2 Cos[w t] Sin[\[Phi][t]] -
M g Sin[\[Phi][t]] == 0,
m y''[t] - m l \[Theta]''[t] Sin[\[Theta][t]] -
m l \[Theta]'[t]^2 Cos[\[Theta][t]] - m A w^2 Cos[w t ] -
M l \[Theta]''[t] Sin[\[Theta][t]] -
M l \[Theta]'[t]^2 Cos[\[Theta][t]] + M y''[t] -
M A w^2 Cos[w t ] - M L \[Phi]''[t] Sin[\[Phi][t]] -
M L \[Phi]'[t]^2 Cos[\[Phi][t]] + m g + M g + K (y[t] - yO) ==
0 , \[Theta]'[0] == 0, \[Phi]'[0] == 0,
y'[0] == 0, \[Theta][0] == 0, \[Phi][0] == 0.5,
y[0] == 0.01}, {\[Theta][t], \[Phi][t], y[t]}, {t, 10}]]
Any help appreciated! Thanks! :)