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A few physics questions

Started by Itskinetic
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Itskinetic

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Not sure if its frowned upon to put a whole bunch of questions into one post, but I was reviewing today and these are the questions that I've thought of. If anyone can answer/explain a few or one, then that would be great if you happen to know it. Or else I'll just look them all up at some point.

1. Salt bridges-- how do these work? I get that its important in order to prevent charge build up that I guess would neutralize the whole system. It's just a little unclear. Where are there negative/positive ions in the solutions in terms of the cathode/anode in say a galvanic cell... are they only for galvanic or electrolytic cells? or both?

2. How can the density of water be 1000 kg/m^3 but 1 kg/L and 1 g/cm^3? Is this right? I'll have to try these conversions out because they don't seem to match up by just looking at it.

3. Kirchoff's laws-- need some practice with these. V= -IR -IR right?

4. For batteries in series, the voltage is additive. For batteries in parallel-- is it just 1/over like in capacitors?

5. are solenoids fair game? need to look up the equation for this then.

6. poles of a magnet? how does a magnet work in general.. north vs. south? field goes from north to south right? why?

7. What are harmonics in sound? how/why are they different? any equations for these?