How do ski jumpers stay in the air for so long?

How do ski jumpers stay in the air for so long?

Transcript¹

Ski jumpers are in the air for about the length of a football field. A physicist² explains how they manage to stay in the air for so long, as the Olympic sport wraps up for the 2022 Winter Olympics.

RACHEL MARTIN, HOST:

We're going to pivot³ now. Ski jumping wraps up today at the Winter Olympics. It's the sport where athletes speed down a big hill and then launch themselves into the air.

LEILA FADEL, HOST:

Ski jumpers are in the air for about the length of a football field.

AMY POPE: Looking at ski jumping, you find people that really look like they are flying. They're staying in the air for 5 to 7 seconds, which is so much longer than anything that we can do here, you know, on the mere⁴ mortal Earth.

FADEL: That's physicist Amy Pope.

POPE: We think about Michael Jordan, who can stay in the air for about a second when he jumps. And these people are managing to fly like a glider⁵ when they really have no extra support.

MARTIN: Pope teaches physics at Clemson University, and she wrote for Smithsonian Magazine about how ski jumping actually works.

POPE: So as the skiers jump off the end of the lift, what they're finding is that the air is rushing on them. They're falling down because gravity is pulling them down towards the Earth. But as they're falling down, the air underneath⁶ them is actually providing a lift force.

MARTIN: So skiers do whatever they can to maximize that effect.

POPE: You'll notice that their skis are splayed in a V-shape and their bodies are nearly parallel to the horizontal. So what they're trying to do is maximize that area so that the wind will push them up.

FADEL: Coordinators need to keep a careful eye on that wind.

POPE: You may notice as you're watching ski jumping that they're lifting and lowering the starting gate based upon the wind speed so that none of the skiers have an unfair advantage by having a large headwind.

FADEL: But Pope says the same wind that's pushing them up is also creating drag.

POPE: That drag is actually serving to slow them down over time, and as they slow down, the lift decreases, and so the flight cannot continue forever, just like anything that sails through the sky.

MARTIN: Now, the physics are so important here that there are very specific rules about what athletes can wear, including their suits. Their suits need to be extremely formfitting.

POPE: If the suits are a little bit loose, what's going to happen is it's going to be like they're wearing a squirrel suit. And they're going to be able to essentially⁷ get more lift because they have a larger surface area that they can present.

MARTIN: Five ski jumpers were disqualified from the Winter Games this year because officials said their suits didn't comply with the rules. But, listen, if you want to see all the physics in play for yourself, the men's final is this morning. Fly, skiers, fly.

[POST-BROADCAST CLARIFICATION: The article that Amy Pope wrote about ski jumping was originally published by The Conversation and was republished by Smithsonian magazine.]

1 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

2 physicist   

n.物理学家，研究物理学的人

参考例句：

• He is a physicist of the first rank.他是一流的物理学家。
• The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。

3 pivot   

v.在枢轴上转动；装枢轴，枢轴；adj.枢轴的

参考例句：

• She is the central pivot of creation and represents the feminine aspect in all things.她是创造的中心枢轴，表现出万物的女性面貌。
• If a spring is present,the hand wheel will pivot on the spring.如果有弹簧，手轮的枢轴会装在弹簧上。

4 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

5 glider   

n.滑翔机；滑翔导弹

参考例句：

• The glider was soaring above the valley.那架滑翔机在山谷上空滑翔。
• The pilot managed to land the glider on a safe place.那个驾驶员设法让滑翔机着陆到一个安全的地方。

6 underneath   

adj.在...下面，在...底下；adv.在下面

参考例句：

• Working underneath the car is always a messy job.在汽车底下工作是件脏活。
• She wore a coat with a dress underneath.她穿着一件大衣，里面套着一条连衣裙。

7 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。