Is theta independent of theta_dot? The last but two row shows when taking partial derivative, we treats the two as two regular variables.

helloCrystal

I think they are not independent since for the rotational kinetic energy, we are replacing angular velocity with the theta_dot, angular velocity should be dtheta/dt

Lockbrains

quite useful page for quiz 12 as well

justaddwater

I feel like I understand this derivation but I'm still confused as to how it works for quiz 12 part 2 of this part when vector is involved

siqiwan2

I have the same question why we ignore that theta_dot when we do partial derivative of theta. From intuition, theta_dot is kind of related to theta?

yee

I believe here we view theta_dot and theta independently. It's something related to the definition of partial derivitive.

Zhuoqian

Lagrangian mechanics is an amazing form of Newton's second law, except extremely tedious to compute.

Is theta independent of theta_dot? The last but two row shows when taking partial derivative, we treats the two as two regular variables.

I think they are not independent since for the rotational kinetic energy, we are replacing angular velocity with the theta_dot, angular velocity should be dtheta/dt

quite useful page for quiz 12 as well

I feel like I understand this derivation but I'm still confused as to how it works for quiz 12 part 2 of this part when vector is involved

I have the same question why we ignore that theta_dot when we do partial derivative of theta. From intuition, theta_dot is kind of related to theta?

I believe here we view theta_dot and theta independently. It's something related to the definition of partial derivitive.

Lagrangian mechanics is an amazing form of Newton's second law, except extremely tedious to compute.