Ive always found so utterly pointless "teaching" this kind of examples in physics classes, its neither physics nor engineering, let alone decent linear algebra: In engineering you use superposition theorems and Thevening and Norton to calculate in seconds those Is and Vs without any risk or also one could apply linear algebra and some circuit or mesh systematic theorems to get invertible matrices. At any rate this kind of exercise leaves neither systematic method nor general useful theorems to never again having to write down almost meaningless equations
Nobody asked that, but it's a good question. I3 is the only current in that segment, and it is given by the junction law at 3:31, namely I3 = I2 - I1. It (hopefully) all works out in the end. Cheers, Dr. A
Good question. When you're following the current and you go across a resistor, the potential drops so you make it a minus sign. Don't get confused by the diagram, up is not positive. Cheers, Dr. A
Inevitably it doesn't matter, as long as you keep it the same through the whole problem When you have the choice between it going up or down, (aka two voltages combine like this one) just choose one, When you finish solving the problem, if you get a negative value that's how you know you chose wrong, but when talking about magnitude the sign doesn't matter so even if you choose wrong your number will still be correct.
I wonder how Physics teachers draw such great straight lines lol. Currently cramming for a final :(
Ahhh yes, the power of editing.
Cheers,
Dr. A
Ive always found so utterly pointless "teaching" this kind of examples in physics classes, its neither physics nor engineering, let alone decent linear algebra:
In engineering you use superposition theorems and Thevening and Norton to calculate in seconds those Is and Vs without any risk or also one could apply linear algebra and some circuit or mesh systematic theorems to get invertible matrices. At any rate this kind of exercise leaves neither systematic method nor general useful theorems to never again having to write down almost meaningless equations
Thank you Mr Anderson 🙏
Supportive enough, where are you lecturing maybe i can follow you ..
Please makes video about thevnins and norton's theorem
Working on it.
Cheers,
Dr. A
Excellent! Thanks!
You're welcome!
Cheers,
Dr. A
How many asked how I1 and I3 could be going in opposite directions in the same 'wire' at the same time?
Nobody asked that, but it's a good question. I3 is the only current in that segment, and it is given by the junction law at 3:31, namely I3 = I2 - I1. It (hopefully) all works out in the end.
Cheers,
Dr. A
why is it -I2(110) ? Isn't it a voltage increase (the loop on the right)
Good question. When you're following the current and you go across a resistor, the potential drops so you make it a minus sign. Don't get confused by the diagram, up is not positive.
Cheers,
Dr. A
Wouldn't a 58V battery just overpower a 3V battery?
Pretty much. Just a random example.
Cheers,
Dr. A
WAIT HOW ARE YOU DOING THAT. CAN U TEACH ME CALCULUS MISTER
I don't teach calculus, just the components we need for our physics. Glad yo're enjoying the videos.
Cheers,
Dr. A
4:00 i didn't understand the middle wire of the circuit. How do we know if the current goes up or down?
Inevitably it doesn't matter, as long as you keep it the same through the whole problem
When you have the choice between it going up or down, (aka two voltages combine like this one) just choose one,
When you finish solving the problem, if you get a negative value that's how you know you chose wrong, but when talking about magnitude the sign doesn't matter
so even if you choose wrong your number will still be correct.
@@syphonx8423 okayyyy thank you soooo much for helpingggg it really means a lottt 😭
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Cheers,
Dr. A
😄