日常生活中的物理
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Getrude Ederle
Gertrude Ederle 1926 - first woman to swim across the English Channel.
Alison Streeter
Alison Streeter has swam the gruelling English Channel more times than anyone.

The 34km (21 mile) English Channel is considered the most gruelling swim in the world. Since Webb's triumph, there have been 6 200 known attempts to swim the English Channel. More than 470 people were successful over 600 times, including a 12-year-old boy in 1979, a 12-year-old girl in 1983, a 65-year-old man in 1983, and a 45-year-old woman in 1975. Mike Read holds the men's record, and Alison Streeter surpassed him with the women's record. Matthew Webb, in search of an ever greater challenge, died attempting to swim the violent whirlpool rapids below Niagara Falls in 1882.

The first woman to swim the English Channel was 19-year old AmericanGertrude Ederle. From 1921 to 1925, Ederle set 29 US and world records for swimming races ranging from the 50 metre (50 yard) to the half-mile race. In the 1924 Summer Olympic Games, she won a gold medal as a member of the championship US 400-meter freestyle relay team, at only 17 years of age. On 6 August 1926 she crossed the English Channel in 14 hours and 31 minutes - 2 hours faster than the men's record - setting a woman's world record that stood for 35 years. It brought her even further international acclaim, and a ticker parade in New York. Sadly, she became partially deaf as a result of her Channel swim.

Swimming the open ocean, any ocean, is no easy feat. The water is icy cold, the tides are fierce, and the traffic of tankers and ferries is daunting. Such huge challenges, however, seem to be the thriving factor for the most brave. One of whom is Alison Streeter, a thirtysomething currency trader from London. Known as "Queen of the Channel," she has swum the chilly Channel more times than anyone else - 37 crossings to date. Streeter first swam the Channel at 18, is the first woman to swim the 'double', and the only woman ever to have completed the 'three-way' to France, back and to France again.


以下僅就 長泳一項以物理的觀點提出: 男人與女人 在 長泳 運動上的差異性。

一般說來 男人與女人 在身體結構上 有著先天的差異性。

    男人身體肌肉所佔比例較多(約比女人多出 20%),而女人則脂肪佔較多比例。
      肌肉內70%是水,20%是蛋白質。你想身體內最強壯的肌肉是那裡的肌肉?

      那個器官裡的肌肉每天運動約十萬次左右? 參考答案

肌肉的密度 大於 脂肪的密度,因此 男人身體的密度往往大於女人。
    所以 女人通常較男人 容易漂浮在水面上。(人的密度只比水略少)
男人肌肉又大多分佈於上半身,手臂上男人多肌肉、女人則含較多脂肪。

女人的脂肪 除胸部外 ,臀部也佔不少比例,

重心高對於跳高或撐竿跳等或許稍佔便宜,
    但是對於游泳 重心高過浮體中心, 則上半身易下沈而吃虧。
女人的皮膚由於含較多脂肪,體態較呈曲線。男人則由於筋骨露出而顯得粗獷。

在短途游泳或許差別不大,但長泳時曲線的體態所受水的阻力較少則顯示其優異性。

    男人則更適合於強有力肌肉所提供需要爆發力與速度的短程運動。
在冰冷的水中游泳時,由於體內外的溫差而有熱傳導。
    肌肉的熱傳導比起脂肪好很多,也就是肌肉比脂肪更容易傳導熱量,

    因此在冰冷的水中游泳時,男人比女人更快散失體內的熱量。

在長途且冰冷的水中游泳時,女人保溫的能力強過男人。
    更大的差別在於 體內的熱能是靠 脂肪的燃燒(化學作用產生熱能),

    較多的脂肪就好像有較多的燃料。

女人含有較多的鬆弛激素賀爾蒙,因此連結骨骼間的韌帶
    有更強的延展性與韌性。(軟骨表演多是女性吧!)
對於長途的跑步或游泳將有較大的優勢。
總而言之,脂肪有如提供一件 貼身的游泳救生衣,
    提供燃料、又減低體內熱量散失、增加浮力、減少阻力、降低重心 ...。
難怪 長泳 往往是 女選手的天下。

平常血液循環時攜帶氧氣輸送至身體各部位,約 20%輸送到肌肉。

    激烈運動時則可能提高至80%。
通常小孩子在 青春期以前體態並無多大區別,青春期後則開始有著明顯的差異性。

其實注意觀察 不同的運動, 會發現 選手的體態有著不同的模式,

    籃球選手與體操選手或舉重選手 體格上有著明顯的差異。
    不同的身體型態 適合於不同的運動。
藉此文拋磚引玉,你對於長泳或者其他的運動 是否也有獨到的見解呢?

 


如何量你自己身體的重心?

    雙腳朝後跪在地上,身體平貼地面逐漸往前伸直。

    當身體開始感覺不穩定頭欲觸地時,膝蓋上方身體的部位約是重心所在。

那個器官裡的肌肉每天運動約十萬次左右
    想一想!你的心臟,每分鐘跳動超過 70次。

    將血液在那麼多細細的血管中推動著!



0最後修改紀錄: 2008/01/21(Mon) 22:42:35


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