作者onlyveritas ( 食夢者)
看板Chemistry
標題[問題] 表面張力問題
時間Sat Nov 23 20:27:57 2013
題組，我的問題在第二題，順便連第一題一起附上。
1.In a capillary into, mercury is injected and found the wight increases by
0.03gm/cm and the length of the mercury section is 1.2cm. The density of Hg
is 13.534g/cm^3 Caculate the radius of the capillary tube.
參考答案:
πr^2hd=3.14159 x r^2 x 1.2 x 13.534=0.03
r=2.42x10^-2cm
2.We insert this capillary tube ertically into water and found the water level
raises by 6.18cm at room temperature. The density of water is 0.997g/cm^3.
Please calculate the surface tension of water.
參考答案:
h=2σ/dgr
→6.18=2σ x 980 / 0.997 x 980 x2.42x10^-2
→σ=0.0746gm/cm
我的問題是我不知道為什麼2σ還要再乘上980
請板友指正
謝謝
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