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  • Have you ever played under a parachute at school?

  • You and your friends hold on the edge, flip it up toward the sky, and then slip inside

  • and watch it slowly float down on top of you.

  • Or maybe you've seen a skydiver jump out of an airplane!

  • After he jumps, he falls through the air, and then...he opens up his parachute!

  • The parachute slows the skydiver down, so he falls gently towards the ground and can

  • make a safe landing.

  • But have you ever thought about how parachutes work?

  • Well, in the end, parachutes work because ofair!

  • That's right!

  • The stuff that's all around us!

  • You're breathing it right now!

  • And, air, like everything else that you can feel, or that takes up space, is made

  • of matter.

  • That's what scientists call, just, stuff!

  • Everything is made of matter!

  • The parachute, the air, the ocean, you, me, everything.

  • And since air is made up of matter, when you walk through the air, you're actually

  • pushing matter out of the way, with every move you make!

  • But here's the thingthat matter is pushing back on you, too!

  • You probably don't feel it when you're just walking around.

  • But when you start running, you might feel it a little bit.

  • And when you start to go even faster, like when you're speeding around on your bike

  • Whoa!

  • That feeling is the air pushing against you!

  • And this force has a name: It's called drag.

  • Drag is the force of the air pushing back on you, or on anything, when it moves.

  • And the faster something is moving, the more drag it feels.

  • So, you don't really feel the force of the air as you walk around.

  • But have you ever held your hand outside the window of a moving car?

  • That's some serious drag!

  • You can feel the air pushing against your hand, and it can be hard to even keep it still!

  • But, have you noticed that it's easier to hold your hand flat, like this, than it

  • is to hold your hand so your thumb's pointing up, like this?

  • Why do you think that might be?

  • It's because when you hold your hand straight up like this, more air is bumping into your hand.

  • That's means more drag!

  • But when you put your hand flat, like this, only a small part of your hand is pushing

  • the air out of the way.

  • There's less of your hand for the air to run up against, which means less drag, so

  • your can glide through the air more smoothly.

  • So, what if you're a skydiver, and you're jumping out of an airplane?

  • How do you slow yourself down so you can land safely?

  • You'd want to do something that would make more air bump into you.

  • And that's how a parachute helps; it makes more space for the air to run into.

  • So it creates more drag!

  • There's so much drag on the parachute, so much air pushing against it, that it slows

  • down your fall, so you can land safely.

  • Now, a lot of other things experience drag, too!

  • When a boat moves through the ocean, the water that pushes back against it is also making drag.

  • And cars and trucks experience drag when they're driving down a highway.

  • A little car feels less drag than a big truck, because it has less space for air to push

  • against it.

  • So, drag is the force that you feel when you're moving through something, like the air, and

  • that something pushes back.

  • It may slow you down.

  • But it's what makes lots of things, from skydiving to playtime with parachutes, possible!

  • Thanks for joining us on SciShow Kids!

  • Do you have a question about parachutes, force, or anything else at all?

  • Ask a grownup for help, and leave us a comment down below, or send us an email to kids@thescishow.com!

  • And we'll see you next time!

Have you ever played under a parachute at school?

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A2 初級 美國腔

降落伞的游戏时间|儿童物理(Playtime with Parachutes | Physics for Kids)

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    joey joey 發佈於 2021 年 05 月 07 日
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