力学分析重车撞轻车

来源: Bonbon330S 于 2005-03-02 13:59:58 [] [旧帖] [给我悄悄话] 阅读数 : (1185 bytes)

First, a disclaimer: I'm rusty at physics, even in its most elementary form. But I'll attempt to write down equations, solve them, and explain the results.

Let's assume that two vehicles, of mass m1 and m2, moving towards each other at velocities v1 and v2 (without loss of generality, v1>0, v2
The outcome of this collision is governed by two conservation laws:

1. Kinegic energy is conserved. Thus

0.5*m1*u1*u1 + 0.5*m2*u2*u2 = g * (0.5*m1*v1*v1 + 0.5*m2*v2*v2),

2. Momentum is conserved. Thus

m1*u1 + m2*u2 = m1*v1 + m2*v2.

This set of quadratic equations produce two sets of solutions, one of which under g=1 leads to u1=v1 and u2=v2 (in other words, no collision) and should be discarded. The valid solution can easily be obtained on say Mathematica, and I won't bother to list it here. For the ensuing discussion, it doesn't matter.


所有跟帖： 

• 回复：力学分析重车撞轻车 -Nonsense- ♀ 给 Nonsense 发送悄悄话 (120 bytes) () 03/02/2005 postreply 14:04:15

• That's in the coefficient g. -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (0 bytes) () 03/02/2005 postreply 14:07:03

• u probably misunderstood his -x-boxer- ♀ 给 x-boxer 发送悄悄话 (308 bytes) () 03/02/2005 postreply 14:12:55

• That's addressed in part 3. -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (71 bytes) () 03/02/2005 postreply 14:14:19

• I once chatted with a friend -x-boxer- ♀ 给 x-boxer 发送悄悄话 (511 bytes) () 03/02/2005 postreply 14:33:02

• Also, the steering column -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (81 bytes) () 03/02/2005 postreply 14:48:00

• 力学分析重车撞轻车 (2) -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (899 bytes) () 03/02/2005 postreply 14:06:40

• 力学分析重车撞轻车 (3) -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (1159 bytes) () 03/02/2005 postreply 14:13:13

• 力学分析重车撞轻车 (4) -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (400 bytes) () 03/02/2005 postreply 14:28:21

• 怎么标题是中文,结果进去了是英文啊? -我的英语太差了- ♀ 给 我的英语太差了 发送悄悄话 (0 bytes) () 03/02/2005 postreply 17:04:18

• English title wouldn't fit :) -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (0 bytes) () 03/02/2005 postreply 17:08:32

• Nice talk and formulas -funnycars- ♀ 给 funnycars 发送悄悄话 (202 bytes) () 03/02/2005 postreply 18:39:17

• They have diff. objective. -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (687 bytes) () 03/02/2005 postreply 18:54:49

• 露分析了一个问题 -露分析了一个问题- ♀ 给 露分析了一个问题 发送悄悄话 (102 bytes) () 03/02/2005 postreply 20:22:16

• It's exactly the opposite. -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (644 bytes) () 03/03/2005 postreply 05:21:30

• that is what i say -thatiswh- ♀ 给 thatiswh 发送悄悄话 (40 bytes) () 03/03/2005 postreply 06:16:34

• Hehe, sorry I scanned your -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (295 bytes) () 03/03/2005 postreply 06:35:51

• Energy is not conserved!! -3.14159- ♂ 给 3.14159 发送悄悄话 (354 bytes) () 03/03/2005 postreply 10:34:42

• The formula has a damping coef -Bonbon330S- ♂ 给 Bonbon330S 发送悄悄话 (166 bytes) () 03/03/2005 postreply 10:53:09

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