# Solve two equations of motion?

GROUPS:
 Hi guys, Having a bit of an issue with one of my inputs on mathematica, i have two equations of motion for a complex system and trying to get a solution out of it. Keep getting the error message: NDSolve::ndnum: Encountered non-numerical value for a derivative at t == 0.. But, as far as i'm concerned I have assigned a value to all my variables except the two i'm solving for. My input is below: eq1 := θ''[t] - A w^2 l Cos[θ[t]] Sin[w t] - l g Sin[θ[t]] + (l ϕ'[t]^2 Sin[θ[t] - ϕ[t]] + l ϕ''[t] Cos[θ[t] - ϕ[t]])/α == 0 eq2 := ϕ''[t] - (g Sin[ϕ[t]] + A w^2 Cos[ϕ[t]] Sin[w t] + l θ'[t] Sin[θ[t] - ϕ[t]] - l θ''[t] Cos[θ[t] - ϕ[t]])/L == 0 With[{g = 9.81, α = 20, l = 1, L = 1, A = 1, w = 50}, sol = NDSolve[{eq1, eq2, θ'[0.1] == 5, ϕ'[0.1] == 1, θ[0] == 0, ϕ[0] == 0}, {θ[t], ϕ[t]}, {t, 10}]] NDSolve::ndnum: Encountered non-numerical value for a derivative at t == 0.. Thanks.