I was in my first year of a physics degree 20 years ago. I wasn’t that motivated in the field and I changed direction to medicine. Revisiting these topics now is satisfying . These videos are excellent.

Very helpful video ..I am from Indian in rural area ... thanks you so much I over country education is very expensive .we don't afford .like this ..👍

Amazing video... but how do you write right in this glass?

Fantastic derivation! Thank you!

Very helpful! Thanks for nice video

Thank you so much! Professor!

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Dear Professor Chasnov, what a great resource, thank you very much. My Question: At 4:55 in the video you state the unit vectors are independent of "r" and you disregard the d/dr contribution. (presumably because the d/dr of a constant = 0). It is not obvious to me why the unit vectors are independent of "r". Can you please point me to a resource that might explain this further? Much Thanks! Kind regards, Rick

During Divergence formula , 1st term i think we consider ∂r^/∂r = 0 - can anybody remind me why ?

Regarding Equation of Divergence, Shall it 2 terms as per Dot product definition ∇.U= (r^ ∂/∂r + θ^ ∂/∂r 1/r) . ( Ur r^ + Uθ ∂/∂θ) = r^ ∂Ur/∂r + θ^ ∂U θ /∂r 1/r Why we make complete multiplications for two parts of divergence?