歡迎閱讀《週末科學版》!我們每週五都要為你介紹可以在家中進行的有趣科學實驗。你可以在《科學日誌》中記錄自己做了哪些活動,這樣就可以將所學的記錄下來,比較這些結果,也許還可以利用它們來設計新的實驗!先看一下《科學日誌》的點子再開始吧。展開實驗之前,記得要獲得大人許可喔!
The first human-powered, heavier-than-air flight took place in North Carolina in 1903. The airplane was designed and built by the Wright brothers, after years of unsuccessful attempts.
Even though the Earth’s gravitational pull is very weak, it’s very difficult to escape it for very long. However, airplanes are somehow able to consistently cheat gravity. In today’s experiment we’re going to show you why airplanes can fly, using only a hairdryer and a ping-pong ball.
PHOTO: AFP
(JOHN PHILLIPS, STAFF WRITER)
世界第一架由人力發動、比空氣還重的飛機,一九O三年在美國北卡羅萊納州升空,萊特兄弟經過多年失敗的嘗試後,才設計打造了這架飛機。
雖然地心引力十分微弱,但要長時間�?牏O卻極為困難。然而,飛機因為某種原因卻能持續抵抗地心引力。今天的實驗中,我們將利用吹風機和一顆乒乓球來說明飛機的飛行原理。(翻譯:袁星塵)
METHODOLOGY 方法
Turn on the hairdryer and suspend a piece of tissue paper over it. You can identify the direction of the air stream by noticing which way the tissue blows.
Now carefully place the ping-pong ball into the air stream. The ball stays suspended above the hairdryer. Very carefully reach in and pull the ping-pong ball partially out of the air stream. You will notice that the air stream sucks the ball back into it.
With the ball still suspended on the air stream, hold the hairdryer close to a wall. Notice the height of the ball increases.
打開吹風機,把一張衛生紙懸放在其出風口。你可以藉由觀察衛生紙吹動的方向,辨認出氣流的方向。
接著,小心地把乒乓球放置在這股氣流上;乒乓球會飄浮於吹風機上方。非常小心地把手伸近這顆球,將它稍稍拉離氣流。你會發現,氣流會把乒乓球吸回去。
保持乒乓球懸浮在氣流之上,然後把吹風機靠近牆邊。注意觀察球的高度增加多少。
HOW IT WORKS 實驗原理
When the ball is suspended above the hairdryer, the high air pressure beats the Earth’s gravity and the ball floats. When you pull the ball partially out of the air stream, the air arcs round the curvature of the ball creating an area of low pressure. The normal air pressure on the other side of the ball is higher and therefore pushes the ball back in to the air steam.
The reason the pressure drops is based on a principle that states, “when air speeds up, its pressure drops.” When you walk closer to the wall, the air cannot expand anymore so it creates an area of even higher pressure under the ball, which forces the ball higher up.
當球懸浮在吹風機上方時,吹風機吹出的強大氣壓大過地心引力,使球懸浮在空中。當你將球部份拉離這道氣流時,乒乓球周圍循彎曲弧線行進的氣流會使該區氣壓降低。乒乓球另一邊的正常氣流氣壓較高,因此會將球推回原本的氣流。
乒乓球一邊的氣壓之所以會降低,是基於「氣流速度增加時,氣壓會降低」的科學原理。當你走近牆邊,空氣再也無法擴張,以致乒乓球下方形成一個氣壓更高的區域,這股力量迫使乒乓球浮得更高。
AERODYNAMICS 空氣動力學
We still haven’t really explained what allows airplanes to take off and remain in the air. The answer has to do with air pressure and aerodynamics. If you hold your hand out of a moving car window then tilt your hand upwards to force the air to flow down, you’ll notice that your hand seems to rise up.
This is exactly what airplane wings do. Last week we learnt about Newton’s third law, which states that for every action there is an equal an opposite reaction. An airplane wing forces air downwards. The opposite reaction is that the air forces the plane upwards. As long as the wings continue to force air downwards the plane will stay in the air.
我們還沒真正解釋飛機是怎麼飛上天且在空中巡航的;答案和氣壓及空氣動力學有關。如果你在行進中的車上把手伸出窗外,然後把手向上傾翻,迫使空氣向下流動。你會發現,你的手好像會浮升。
這就是飛機機翼的原理。上週我們學過牛頓第三定律,即每個作用力都會有一個等量且方向相反的反作用力。飛機的機翼迫使空氣向下,而反作用力就是迫使飛機上升的氣流,只要機翼持續迫使空氣向下,飛機就會維持在空中。
The strongest earthquake to hit Taiwan in 25 years killed at least 16 people and damaged dozens of buildings, but the destruction was largely contained thanks to decades of preparedness work. Taiwan sits on the “Ring of Fire,” an arc of intense seismic activity along the Pacific Rim, and — much like neighboring Japan — has a long history of catastrophic quakes. How does April 3 compare with other recent quakes? The April 3 earthquake, which measured 7.4 on the moment magnitude scale, was felt across Taiwan. It was the most severe since a 7.6 magnitude quake in 1999 killed
A: Artificial intelligence technology has been causing controversy lately: a student was caught cheating with AI to win the grand prize in an art contest. B: That’s so absurd. Does this mean that AI paints better than humans? A: Maybe. Luckily, the student was later disqualified. B: And more absurdly, it’s becoming more and more popular to use AI technology to “resurrect” people. A: Yeah, some netizens even posted videos featuring the late singer CoCo Lee, who was “resurrected” by them with AI software. A: 人工智慧的爭議不斷,有學生違規使用AI參加美術展,甚至贏得首獎。 B: 真誇張,這是不是代表AI比人類還強大? A: 或許吧,幸好得獎資格被取消。 B: 還有更誇張的︰讓死者重現的「AI復活」技術越來越熱門。 A: 對啊,還有網友製作已故歌后李玟「復活」的影片呢! (By Eddy Chang, Taipei Times/台北時報張聖恩)
Around the time of the Dragon Boat Festival in June, the streets of Taiwan are filled with the delightful aroma of zongzi, a traditional snack made of sticky rice wrapped in leaves. The leaves are folded into a cone and then filled with sticky rice and other ingredients such as braised pork belly, peanuts and salted duck egg yolks. The filled leaves are then tightly tied with kitchen twine and ready for cooking. 每到六月端午時節,街頭巷尾就會飄出粽子的香氣。粽子是將糯米包進粽葉的傳統美食,先將粽葉折成圓錐狀塞入糯米,以及紅燒肉、花生、鹹鴨蛋黃等配料,用棉線綁緊後即可烹煮。 Dragon Boat Festival (n. phr.) 端午節 aroma
It’s another school day with the same ritual. You wake up to your smartphone’s alarm, scroll through messages during your commute, and listen to your favorite playlist with your wireless earbuds between classes. These devices, integrated smoothly into your daily routine, certainly make life more convenient. However, where do these devices end up after you replace them? In fact, the issue of electronic waste is a growing global concern. According to the United Nations, in 2019 alone, we generated an astonishing 53.6 million tons of e-waste—an average of 7.3kg per person. Projections hint at the figure soaring to 110