Good job Brian. Nice and clear. Good pace, and extra simple.
@바깥고리
10 ай бұрын
Thank you!
@engineerahmed7248
3 ай бұрын
He got complete grasp of subject...Wish used 8 times bigger white board
@esaff3761
Жыл бұрын
@3:58 here I have confusion. I think in (dL/dt)rot, L would always be zero . Because rotating frame is rotating along with rigid body, so *angular velocity must be zero according to observer in rotating frame* and hence at every instant *angular momentum must also be zero according to observer in rotating frame*....
@바깥고리
10 ай бұрын
In my opinion, Rotating frame is rotating with angular velocity. But angular momentum vector can not be parallel with angular velocity vector so (dL)rot comes.
@바깥고리
10 ай бұрын
I think it would be a answer. dL/dt (rot) means rate of change of L(angular momentum for fixed reference frame) measured in rotating frame.
@ashutoshsingh450
5 жыл бұрын
Thanks 🙏🏽
@playumayap9351
6 жыл бұрын
If I want to find the torque necessary for a body to keep rotating about a fixed axis, is this what I use?
@brianjackson828
6 жыл бұрын
Depends on the specific situation, but probably yes, these are the equations you want.
@playumayap9351
6 жыл бұрын
A cuboid rotating about one of it's sides but I'm not sure how to go about this. I find the lambdas by finding the inertia tensor in the principal coordinate system (which I guess is origin at CM and axes parallel to the cuboid's sides), but then what?
@brianjackson828
6 жыл бұрын
So the question is "What torque is required to keep the rotation vector fixed?"? If that's the question, you need to figure out how to write the rotation vector in the body frame, giving you omega 1, 2, and 3. Then, using Euler's equations, you need to figure out what torques Gamma 1, 2, and 3 are required to make the time derivatives of the omegas equal to zero.
@playumayap9351
6 жыл бұрын
That makes sense, thank you!
@benebeck5628
3 жыл бұрын
thx bro
@dbgsdc3913
Жыл бұрын
Sir are u a German
@brianjackson415
Жыл бұрын
I am not. : )
@esaff3761
Жыл бұрын
@@brianjackson415 @3:58 here I have confusion. I think in (dL/dt)rot, L is always zero . Because rotating frame is rotating along with rigid body, so *angular velocity must be zero according to observer in rotating frame* and hence at every instant *angular momentum must also be zero according to observer in rotating frame*....
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