- #1
DannyS
- 3
- 0
I am trying to input the equation of motion for a pendulum:
θ1'' = −g (2 m1 + m2) sin θ1 − m2 g sin(θ1 − 2 θ2) − 2 sin(θ1 − θ2) m2 (θ2'2 L2 + θ1'2 L1 cos(θ1 − θ2))
L1 (2 m1 + m2 − m2 cos(2 θ1 − 2 θ2))
with θ2 and θ2'2 being the only unknowns but I am not getting the results that are needed. Can someone please check if there are any mistakes in my equation.
NDSolve[{20.64*-Cos[
6.3 t] == ((-9.8*(1.61)*
Sin[.52*Sin [6.3 t]]) - (1.61*9.8*
Sin[Sin [6.3 t] - 2 Theta[t]] - (2*
Sin[Sin [6.3 t] -
Theta[t]])*1.61*((Theta'[t])^2 *0.48 + (3.21*
Cos[6.3 t])^2*.3*Cos[.52*Sin [6.3 t]] -
Theta[t])/(.30 (1.61 -
1.61*Cos[2*.52*Sin [6.3 t] - 2*Theta[t]])))),
Theta[0] == 10000}, Theta[t], {t, 0, 10}]
Thanks!
θ1'' = −g (2 m1 + m2) sin θ1 − m2 g sin(θ1 − 2 θ2) − 2 sin(θ1 − θ2) m2 (θ2'2 L2 + θ1'2 L1 cos(θ1 − θ2))
L1 (2 m1 + m2 − m2 cos(2 θ1 − 2 θ2))
with θ2 and θ2'2 being the only unknowns but I am not getting the results that are needed. Can someone please check if there are any mistakes in my equation.
NDSolve[{20.64*-Cos[
6.3 t] == ((-9.8*(1.61)*
Sin[.52*Sin [6.3 t]]) - (1.61*9.8*
Sin[Sin [6.3 t] - 2 Theta[t]] - (2*
Sin[Sin [6.3 t] -
Theta[t]])*1.61*((Theta'[t])^2 *0.48 + (3.21*
Cos[6.3 t])^2*.3*Cos[.52*Sin [6.3 t]] -
Theta[t])/(.30 (1.61 -
1.61*Cos[2*.52*Sin [6.3 t] - 2*Theta[t]])))),
Theta[0] == 10000}, Theta[t], {t, 0, 10}]
Thanks!