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发表于 21-10-2012 01:04 PM
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发表于 7-11-2012 08:55 PM
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求解：
A ship of mass 3*10^8 kg moves with uniform velocity of 2.0ms^-1.
the ship needs a chained steel anchor to stop the ship in a distance of 20m after the anchor is dropped.
calculate the average tension of the chained anchor. |
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发表于 11-12-2012 11:32 PM
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red_snail 发表于 7-11-2012 08:55 PM 
求解：
A ship of mass 3*10^8 kg moves with uniform velocity of 2.0ms^-1.
the ship needs a chained ...
请问你这题有 solution 了吗？答案是 3.0 x10^7 N 吗？
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发表于 25-3-2013 10:12 PM
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为什么一个block 里面的electron的drift velocity和那个block 的速度一样时，那个hall's voltage 会不见掉？ |
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发表于 18-4-2013 05:28 PM
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发表于 17-5-2013 10:59 PM
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"The frequency f of the note produced by a stretched string depends on its length l, the tension T of the string and the mass per unit length m of the string. Use the method of dimension to derive an equation for f."
anyone can help me to solve this problem please~ |
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发表于 17-5-2013 11:02 PM
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"The frequency f of the note produced by a stretched string depends on its length l, the tension T of the string and the mass per unit length m of the string. Use the method of dimension to derive an equation for f. "
anyone can help me to solve this question please~ |
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发表于 30-5-2013 09:19 PM
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The dimension of frequency, f is T^-1
The dimension of length, l is L
The dimension of tension, T is MLT^-2
The dimension of mass per unit length, m is ML^-1
Start from tension,
since frequency has only time in its dimension, remove M first,
[T/m = (L/T)^2]
Then, remove L,
[T/(ml^2) = T^-2]
Square root the equation,
[(1/l)(T/m)^-2 = T^-1]
Therefore, f = (1/l)(T/m)^-2 |
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发表于 29-6-2013 09:56 PM
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怎么做啊？？？ |
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发表于 30-6-2013 09:43 AM
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请各位帮帮忙^^
At what angle should the ball be thrown so that its maximum height reached is the same as its horizontal range?
答案是76’，请问正确的做法应该怎么样？ |
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发表于 30-6-2013 11:53 PM
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基纳人 发表于 30-5-2013 09:19 PM
The dimension of frequency, f is T^-1
The dimension of length, l is L
The dimension of tension, T ...
http://i.imgur.com/pr8TJoh.jpg
你会做吗？？？
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发表于 8-7-2013 11:05 PM
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plouffle0789 发表于 29-6-2013 09:56 PM
怎么做啊？？？
纯属参考。。=）
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发表于 8-7-2013 11:15 PM
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makopl 发表于 30-6-2013 09:43 AM
请各位帮帮忙^^
At what angle should the ball be thrown so that its maximum height reached is the sa ...
纯属参考。。 |
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发表于 8-7-2013 11:21 PM
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发表于 8-7-2013 11:49 PM
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影舞 发表于 8-7-2013 11:21 PM
感谢大大帮忙
我们的phy老师可以free fall to ocean，所以我自修
我已经被phy搞到半条命了 ...
你是plouffle？
久仰大名？你认识我？
没什么啦。。只是举手之劳而已。。
凡是在我能力以内的，能帮的就帮下学弟学妹
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发表于 9-7-2013 03:35 PM
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Log 发表于 8-7-2013 03:49 PM
你是plouffle？
久仰大名？你认识我？
没什么啦。。只是举手之劳而已。。
plouffle是虾米东东？？人名？？
没有啦只是听过你的名字 XD
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发表于 9-7-2013 08:45 PM
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Log 发表于 8-7-2013 11:15 PM
纯属参考。。
谢谢前辈赐教。.gif)
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发表于 14-7-2013 12:55 PM
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plouffle0789 发表于 29-6-2013 09:56 PM
怎么做啊？？？
不好意思，想请问你这些题目是什么书找的啊，因为我正在准备sem 1 的物理考试所以想要拿更多的课外书来做。谢谢。
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发表于 19-7-2013 07:58 PM
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请问这里有人会这个 A-level 的 practical 的问题吗？
因为我不懂可以 post 在那里 ... 所以就 post 在这里了 ...
我的老师是新老师，完全没有经验，
我们根本不明白他在解释什么，感觉很无助 ... |
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发表于 9-8-2013 11:28 AM
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newton's law of gravitation的formula是GMm/r^2 or -GMm/r^2,为什么有些书有negative有些没有的?
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