Dynamics - Rigid body rotation example 2

Thermodynamics: drive.google.com/file/d/1bFzQ...
Mechanics of Materials: drive.google.com/file/d/1P-pc...
Statics: drive.google.com/file/d/1aYY5...
Dynamics: drive.google.com/file/d/1_JTk...

[@megata6184]

Mate your too good

[@HashemAljifri515]

When you took the summation of moments why didn't you consider the weight of the block?

[@engineeringdeciphered]

Because I was summing the moments about the center, and the weight goes straight through the center so there it causes no moment.

[@HashemAljifri515]

@engineeringdeciphered You considered the tension but you didn't consider the weight of the 20kg block? Is it possible to draw a fbd for the pulley only and not consider the weight of the block that will cause ccw rotation? 5:08 T is not equal the weight of the block

[@engineeringdeciphered]

⁠​⁠@@HashemAljifri515 I see. Yes, when looking at the pulley, you do no think about the “weight” of the block, the pulley feels the “tension” T caused by the block. Notice on the FBD for the pulley, there is no weight of the other block, only the T. And yes, the T is not equal to the weight of the block because the block is accelerating. If not accelerating, the T would be equal to the weight. So, I think for what you are asking- yes your free body diagram for the pulley does not consider the weight of the block, only the tension.