- #1
swademc
- 0
- 1
- How did you find PF?
- I was reading about resistive power loss: P = I^2R and came across a question about how to understand it more intuitively. The answers did not satisfy me.
Forget the mathematical derivations because the answer is wind (and you know it). It too has an exponential relationship with energy loss, and you can experience it yourself.
It's not too hard to pedal a bike at 20km/h, much less easy at 30km/h, and almost impossible at 40km/h with respect to the wind. The energy lost to wind resistance (ultimately heat) increases exponentially with wind speed. This is also why cars with double the power can't go double the speed.
In a similar way, a linear increase in current flowing through a circuit will result in an exponential increase in resistive losses (heat).
This is just another example where electrons behave somewhat like a fluid. They're bumping around and losing energy when they "hit" stuff. For some reason it's exponential. Don't question it unless you really need/want to.
Use a combination of experience, intuition and maths to solve your problems, and don't get caught up with the people who will inevitably say "err, that's technically not how that works, you should derive everything from quantum theory", because in most cases it doesn't matter how things work. It only matters that they do.
Now go and get some.
(sorry physicists, I'm an engineer)
It's not too hard to pedal a bike at 20km/h, much less easy at 30km/h, and almost impossible at 40km/h with respect to the wind. The energy lost to wind resistance (ultimately heat) increases exponentially with wind speed. This is also why cars with double the power can't go double the speed.
In a similar way, a linear increase in current flowing through a circuit will result in an exponential increase in resistive losses (heat).
This is just another example where electrons behave somewhat like a fluid. They're bumping around and losing energy when they "hit" stuff. For some reason it's exponential. Don't question it unless you really need/want to.
Use a combination of experience, intuition and maths to solve your problems, and don't get caught up with the people who will inevitably say "err, that's technically not how that works, you should derive everything from quantum theory", because in most cases it doesn't matter how things work. It only matters that they do.
Now go and get some.
(sorry physicists, I'm an engineer)