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Stop with the over bright HDR. Just cause you can doesn't mean you should.

Ha, I loved this! Also, i don't think it's just "kids" who record bad data, I'd say there are a bunch of scientists at top universities who just might need to be watching this, just replace average with p-value.

I hope your battery and interconnecting wires had enough internal resistance that the ammeter was not damaged.

A ammeter is a low-impedance device, a dead short in effect. The light bulb goes out, the ammeter goes to fsd and the battery is discharged or dies. Don't try this with a car battery or you will destroy the ammeter too!

you got some cool toys mate😂 it is facinating how much engeinering is in making cars. make me apprciate the hard work

Have a look at resistance wire extensometers. Same principle. Useful thing to know.

As an electrician, I answered this in a few seconds. R goes up as the length goes up.

great video thanks, reminded me of paul hewitt conceptual physics. he also had a very engaging way to explain complex ideas and make physics fun to learn good memores.

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Interesting thanks

R = ρ L /A. Wire resistance is important when sizing electrical wire to carry current since resistance can cause heating and failure when wire is undersized for the current it must carry.

start with 2 resistors in parallel and connect them in series instead

Wish this guy was my math teacher 50 yrs ago, I most likely would of passed.

Another way to think about it, is to think of a pipe and stretching that pipe to double its length. Water will have a tougher time getting through the stretched pipe, so you know resistance will increase.

Gary Oldman knows math!

I have a resistor stretcher, to get custom values.

Why anybody would find it difficult to answer this, I don't understand. The resistance of wire per unit length (at a sufficiently low frequency to avoid the complication of the skin effect) varies inversely with the cross sectional area. If the wire is stretched to double the length, it halves the cross section area, which means the resistance per unit length must be doubled. However, the resistance of the wire also varies linearly with its length, and as the wire is now twice as long, and has twice the resistance per unit length, it means the overall resistance is quadrupled. Normal caveats apply, such as the cross-sectional area remains constant along the length, the current is low enough that there is no significant heating effect (which increases resistance in metals) and so on.

I have been trying to understand how this circuit works since I discovered it in one of Mim's books. I saw it all except how the capacitor discharged, and have been combing the internet where this is explained many times, but poorly. You did it! Just by speaking about the capacitor discharging and pointing, you gave me the missing piece of the puzzle. Thumbs-Up and Subscribed!

Interesting... additional assumptions... wire will conduct end to end, current/ voltage and amperage the same and not enough to melt or significantly heat the wire..

Now I feel dumb but smarter

does electricity have sound. as a kid I loved playing with subwoofers. and used a power cord to plug it in the wall to see what would happen.i never do it again. it stated vibrating bounded off the floor popped the center cone out then started to smoke. so yes there is a sound. then you're deaf and smelling shit.

who else thought the buzz at the end was their own equipment for just a sec

That is not a product of electrons colliding with their environment, each other or transitioning between orbits or between atoms. The 60Hz is just a cheap go at an artifact. For purposes of demonstration the output of your measuring or recording method would have to be altered to put such an event as an electron changing its position, (which is the only way it could possibly make a noise in and of itself) within the range of human perception. Here's one for the smart people. When an electron changes its position within an atom or to a new-to-it atom does it change with perfect instance or does it ring a bit within its new home before it settles down? To me the observable event of the transition and stabilization would be the sound of electricity. Not the electromagnetic ramifications imparted onto objects like a pair of colliding transformer core plates.

Your sound source, purely visually, should be rated for about 500 watts, and you're connecting it to an 18-watt source. Well, that's not serious. Let's go full power. 😉😉😉

I once assembled acoustic systems myself and when I look at your sound source I have only one question: How will you mount it in the body of the acoustic system? I do not see any fastening elements. I have the impression that such a sound source, at full power, will simply fly out of the body of the acoustic system in half a minute.

Thanks Dr. Wargo, this is very interesting and I enjoy your full explanation. I am impressed with your ability to use formulas to make these calculations. You make math cool.

The fan produces an area of lower pressure in front but some of the air in back gets recycled as a toroid so it's not very effective in this scenario. If you prevent the recycling with a duct and increase the power it'll probably start moving forward from the vacuum, because the energy in the vacuum is equivalent to the energy of the air expelled but not all the air expelled does work on the plate (you can tell because it shoots out at high velocity from the sides).

The Mythbusters did this experiment at full scale, with an actual boat on water and proved that the air rebounding off the sail did in fact move the boat forward surprisingly well, just extremely inefficient.

You get some motion, briefly, because the moving components of the device are not equal in mass. And then it jerks back into place because the carriage smacks to a halt, and equilibrium is maintained. And this is why I'm bad at tests, overthinking it.

I think you should have also illuminated both LEDs together and spun them as a control

The lamps will both illiminate bit alternate at the frequency of the AC power. 60 Hz since he seems to have a US accent. 50 Hz in yhe redt of the world. It may allear as both on together though due to filiment heat and visual preception time. Each diode will block half the wave. Since they are oppsite they will block the opposite side. 99%

Blue 40%

Why would anyone be surprised? You could see the top shifting at the start.

I imagined them hitting my face, and decided that the basketball would exert more force.

360 mph is fast enough that air resistance is very significant

I was right the entire aperatous fell over on its side after bouncing a bit

Well done, but when does the Star Gate come into affect?

Yes it's possible, if the sail is curved correctly. It redirects the air.I've seen it done. It's not very efficient but it works well enough that 727 and DC-9 jetliners can reverse from the gate without a tug to push back.

Nice vid sir!

It'a the same principle as letting go of an extended slinky from the top.

And this is why rockets work in the vacuum of space.

I think it would have been helpful to repeat 2:45 in slow motion before continuing the discussion.

You asked, "If I were to pull my mass over while it was on wheels and let it go, what would happen?" The answer is, the entire apparatus would move in the direction that you pulled the mass. You didn't stipulate that you were going to hold the apparatus in place while you pulled on the mass. You may think this answer sounds trivial, but it is the correct one based on the parameters you gave. Now after zooming in to read the printed test, that's a different question.

1. holding the apparatus and the pendulum before release is cheating compared to the problem description. 2. What age are those typical student responses? I can't imagine one who has heard of conservation of momentum giving those answers. This really shocked me, the education system is definitely a system but the education part has been going downhill fast.

I have to say I'm still confused here. I understand that the impulse is given by the difference in momentum, and the basketball's impulse has to be larger as a whole given its bounce. However, the average force is given by the impulse over the collision time, and I assumed the collision time would be larger for the basketball (again, since it would bounce). Why did the time not become a factor in our analysis here?

You imparted a preload in this so the state was not zero I contest You by pulling the weight up to the upright have some of Your energy in play? Yes/no

That's what I thought, but what if the pendulum itself, is dangling a spinning wheel?

Consider your wife or girlfriend driving her new SUV to a birthday party with the windows up and a beautiful bouquet of balloons freely floating in the back hatch area. They are suspended just below the roof and not brushing the sides nor seats. A traffic light unexpectedly turns red and she hits the brakes hard. Which way do the balloons drift? A. Forward B. Rearward C. Sideways D. None of the above Imagine getting pelted by 6 angry balloons. Lol. My wife was incredulous until we had opportunity to test it empirically. How fun that was.