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  • Hey Nige, can you get me another coke?

  • Nah, I'm good, thanks.

  • It's just downstairs.

  • Nah, the tennis is on.

  • You come to my house to watch the tennis and you're not even going to get me another coke?

  • Yeah, it's the tiebreaker. Relax.

  • You know what I wish we had? Like a really long straw so we don't even have to go downstairs to the kitchen.

  • That would be pretty good. Yeah. Yeah. Right?

  • How long of a straw could we actually make that you could use?

  • Downstairs is a bit of a stretch I reckon. Yeah. How much is that, like, 3, 4 meters? Do you think we could?

  • I reckon we could do it.

  • We'd need a lot of straws though.

  • We got a pack here.

  • Oh, okay.

  • Now our first test, just to see that Nigel can use a straw properly, we've got about a 1 meter length of straw here.

  • Think you can suck through that?

  • I could give it a go. So we just taped these drinking straws together, and hopefully

  • Yeah, that's alright. But there's a lot of air coming through I think from the

  • The joints in the straw, yeah. We've gotta come up with some better way to test this out.

  • I happen to have 6 meters of plastic tubing here.

  • Non-toxic?

  • Uhh, that's what they said at the hardware store.

  • We're preparing the preliminary tests. Nigel is lowering some tubing off the balcony.

  • He actually thinks he's got a shot at sucking through 6 meters of tubing

  • I think he's got no chance and he's going to be nowhere close, but

  • I think this will allow us to establish how much Nigel actually sucks.

  • (laughing)

  • He's getting ready up there. He knows there's a lot riding on it.

  • When you're ready!

  • Look at that! Look at that! Woah, he shoots up!

  • He's got 2 meters! He's got three meters!

  • Look at that guy go! He's getting 4 meters, 4 meters!

  • 5! 5 meters! 6!

  • Yeah! (Cheering)

  • Now I'm going to try to do the same thing, but the tube I'm using has a thicker diameter.

  • Mine is about 5 mil, where as Nigel's was 3mil.

  • So we're going to see if this makes any difference.

  • (Inspiring music)

  • Now, I guess the obvious question is, can Nigel do it?

  • Yes

  • Nigel thinks that's the obvious answer but I'm pretty sure he's going to fail.

  • Now, maybe what's worth talking about is how a straw works in the first place.

  • How does it work?

  • Yeah, cause this is really just a big bendy straw. If we look at a smaller version of a straw here

  • We should all be familiar with how this works. Or should we?

  • I don't know. I think most people think you're just sucking the liquid in and swallowing it.

  • But, you knid of have to think about air pressure.

  • Yeah, because actually what's happening is that air pressure is causing the, coke in this case, to go up the straw.

  • Well there's a difference in pressure in the atmospheric pressure and the pressure that you create

  • by opening up your lungs and pulling your diaphragm down.

  • So you reduce the pressure in your mouth, and it's that difference in pressure

  • between the atmospheric pressure and the pressure inside you

  • which gets that liquid flowing into you.

  • someone has failed at the 5 mm diameter and you're the next guy to take it on.

  • You ready for this?

  • I am ready.

  • He's been practicing his whole life for this.

  • Yeah, you can see it's a strong start.

  • Strong start from Quan

  • You've got it. Oh, he's going big right here.

  • You can see there's a lot of determination.

  • He's getting close, getting close. Look at this.

  • Look at this. Can he do it? Can he do it?

  • Ohhhhhh, and he's done it!

  • (cheering)

  • Agh. That tastes disgusting.

  • Yeah I definitely felt like my tounge, while I was trying to suck it up

  • was being pulled out into the straw

  • (off) I felt the same thing

  • But.

  • And it was tougher, definitely tougher.

  • Well done sir.

  • Thank you. Means a lot.

  • For his next challenge, we're going to try to get him to suck through 10.3 meters

  • which is the theoretical maximum, size of straw

  • How are you feeling?

  • Well, that theoretical maximum, kind of relies on being able to get a perfect vacuum

  • and, although I am perfect in a lot of ways, I don't know that I can create a perfect vacuum.

  • I have often thought that there is actually a perfect vacuum inside Nigel's head

  • Today we're going to really find out, won't we?

  • Ok, we've got the setup here. We're down at Tamarama Beach

  • And we have 10.5 meters worth of tubing

  • Which goes all the way up to Nigel at the very top there.

  • So I'm going to see if I can relive some of my former glory

  • and get the red liquid up this height.

  • 3! 2! 1!

  • There you have it. Nigel is starting to suck on that straw.

  • There he goes.

  • Looking strong. Create that vacuum.

  • Approaching the edge of the cliff there. Go, Nigel, Go!

  • C'mon, Nigel!

  • Doesn't seem to be going anywhere. We seem a bit stuck.

  • At that point right there. You can see the determination, the focus.

  • Trying to see how high that is

  • He's done well

  • But it just doesn't look like it's going to happen.

  • (Music stops, and breaks down. Signalling failure)

  • Alright, so Nigel did pretty well there

  • We saw that he could get that liquid up the tube about 7 meters.

  • Not the theoretical maximum of ten meters.

  • Still more than you. Just saying.

  • That's a good point. That's a good point.

  • If Nigel could have created a perfect vacuum, then the water would have

  • gone up to 10.3 meters, according to our calculations.

  • This is kind of similar to how they used to measure atmospheric pressure in the old days.

  • by millimeters of mercury.

  • So atmospheric pressure would push mercury up a tube with a vacuum at the other end

  • 760 millimeters.

  • 760 millimeters. So about .76 of a meter.

  • So you can see why they used mercury and not water

  • because if you were doing this with water, you'd need

  • a cliff

  • yeah, you'd need a ten meter long barometer.

  • so much better to do it with millimeters of mercury.

  • and of course now we measure it in kilopascals.

  • So anyway, well done Nigel. You really suck.

  • So how do we work out the maximum length of straw that you could suck through vertically?

  • Well think about this. You place the straw into the liquid.

  • and you start sucking from the top.

  • that decreases the pressure at the top

  • and the difference in pressure between your mouth and atmospheric pressure

  • creates a force that pushes the liquid upwards.

  • Now that liquid which is in the straw has a weight

  • which is equal to the volume of the liquid, times its density, times the gravitational field strength.

  • so if we set these two forces equal to each other

  • you can see that the pressure difference must be equal to the density of fluid

  • times its height, times the gravitational field strength

  • and if we sub in the numbers, we can see that the maximum height of liquid

  • that anyone could lift, even if they created a perfect vacuum inside their mouth

  • would be about 10.3 meters.

Hey Nige, can you get me another coke?

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B1 中級

世界上最長的稻草 (World's Longest Straw)

  • 5 0
    林宜悉 發佈於 2021 年 01 月 14 日
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