What Makes a Yo-Yo Yo
悠悠球(YO-YO) 并非一個令人陌生的詞眼,史書的最早記錄出現(xiàn)在公元500年前的希臘;相傳16世紀(jì),菲律賓的狩獵民族在狩獵和格斗使用的器具中,在繩子的前端掛著重物似悠悠的武器,據(jù)悉這是悠悠的起源。大約300年前,悠悠傳到了日本,被形象地叫作“獨輪車”或“錢輪”,深受年輕人的歡迎。18世紀(jì)初葉,悠悠在英國以“王子財寶”、在法國以“諾爾曼悠悠”之名廣為流行,尤其是在法國和英國的上流社會盛行。此后,這種玩具和“悠悠”的名字從法國流傳到世界各地。因為每個球手的風(fēng)格和自創(chuàng)花式都不盡相同,所以悠悠球的技術(shù)花式種類非常繁多,可以說是一個技術(shù)的海洋。目前主流的五個花式組別,每個組別的花式種類都數(shù)以千計,而且每年仍然會有非常多的新花式被研究出來。
Ever wonder what makes a yo-yo yo?
Why do yo-yos come back up again?That's a good question,look! And the answer lies in physics. You may have heard the term “inertia(慣性)”. Inertia is the tendency of something in motion to stay in motion, and something at rest to stay at rest. When you let go of the yo-yo, gravity causes it to start moving down.
Now, because it has a string wrapped around its axle(車軸), the yo-yo will start spinning. By the time it reaches the end of the string, it is spinning fast. And because of inertia, it has a strong tendency to keep spinning.
The string that holds the yo-yo is attached to the axle in its middle. As the string unwinds(卷回), that axle is spinning too. So when it runs out of string, the axle keeps on spinning, causing the string to wrap itself around the other way. That’s how the yo-yo winds(纏繞) itself back up.
Now in most yo-yos, there’s a small loop(環(huán)) at the bottom of the string. The yo-yo can be made to hang in that loop momentarily; that’s called “sleeping” the yo-yo. A quick tug(猛拉)on the string pulls the loop against the axle, increasing the friction(摩擦力) between them.
That momentary increase of friction causes the string to catch on(抓牢) the axle, wrap around the spinning axle, and up comes the yo-yo again.
注釋:
catch on
1.抓牢
The girl kept catching on to her mother's skirt.
小女孩一直緊緊地拉著媽媽的裙子。
2.理解
I don't quite catch on to what she is saying.
我不太明白她在說些什么。
3.流行
It is a nice song and I think it will catch on quickly.
這首歌很好,我想它會很快流行。