- #1
Sekonda
- 207
- 0
Hey,
I'm having trouble with part (d) of the question displayed below:
I reckon I'm doing the θ Euler-Lagrange equation wrong, I get :
[tex]\frac{\mathrm{d} }{\mathrm{d} t}(\frac{\partial L}{\partial \dot{\theta}})-\frac{\partial L}{\partial \theta}=\frac{\mathrm{d} }{\mathrm{d} t}(m_{1}r^{2}\dot{\theta})=0[/tex]
and for the 'r' EL equation I get:
[tex]\frac{\mathrm{d} }{\mathrm{d} t}(\frac{\partial L}{\partial \dot{r}})-\frac{\partial L}{\partial r}=m_{1}\ddot{r}+m_{2}\ddot{r}-m_{1}r\dot{\theta}^{2}-m_{2}g=0[/tex]
In the theta equation I was originally just differentiating the theta with repsects to time, but the r^2 term also has a time dependence, I tried doing this and didn't know where to go from there... I'll have another go.
Any comments are appreciated,
Thanks,
SK
I'm having trouble with part (d) of the question displayed below:
I reckon I'm doing the θ Euler-Lagrange equation wrong, I get :
[tex]\frac{\mathrm{d} }{\mathrm{d} t}(\frac{\partial L}{\partial \dot{\theta}})-\frac{\partial L}{\partial \theta}=\frac{\mathrm{d} }{\mathrm{d} t}(m_{1}r^{2}\dot{\theta})=0[/tex]
and for the 'r' EL equation I get:
[tex]\frac{\mathrm{d} }{\mathrm{d} t}(\frac{\partial L}{\partial \dot{r}})-\frac{\partial L}{\partial r}=m_{1}\ddot{r}+m_{2}\ddot{r}-m_{1}r\dot{\theta}^{2}-m_{2}g=0[/tex]
In the theta equation I was originally just differentiating the theta with repsects to time, but the r^2 term also has a time dependence, I tried doing this and didn't know where to go from there... I'll have another go.
Any comments are appreciated,
Thanks,
SK