我來試試

Given:
Vg=40, Va=43, Vm=46, Vp=50, 7.5% difference
M1(5200 lb) is poor, M2(3200 lb) is good

Solution:
M1 以V=40 撞牆後完全停止，其Vi=40，Vf=0
delta P1=5200*40=208000，結果：poor

M2 以V=40 撞牆後完全停止，其Vi=40，Vf=0
delta P2=3200*40=128000，結果：good

如果以40對撞，完全非彈性碰撞（個人認為更接近實際情況）
M1*40+M2*(-40)=(M1+M2)*Vf
Vf=9.5

delta P1=5200*(40-9.5)=158600
result：
158600/208000=76%
decreased by 24%, from poor to good

delta P2=3200*(40+9.5)=158400
result：
158400/128000=1.23
increased by 23%, from good to poor

所有跟帖： 

• 完全正確 -BDXDL- ♂ (812 bytes) () 10/07/2014 postreply 10:32:10

• What's the second Vf? -MoonRiverMe- ♂ (76 bytes) () 10/07/2014 postreply 11:41:37

• 完全非彈性碰撞，兩車碰撞完後， 速度都是Vf -BDXDL- ♂ (96 bytes) () 10/07/2014 postreply 11:54:34

• Your question indicates that you forgot high school physics some -CW62- ♂ (0 bytes) () 10/07/2014 postreply 12:27:16

• Wait a minute, let's see who forgot what after I got off work -MoonRiverMe- ♂ (0 bytes) () 10/07/2014 postreply 13:23:01

• let me ask one thing -MoonRiverMe- ♂ (357 bytes) () 10/07/2014 postreply 16:10:49

• Let me tell you -CW62- ♂ (608 bytes) () 10/07/2014 postreply 17:33:14

• This subject is meaningless to begin with -MoonRiverMe- ♂ (329 bytes) () 10/07/2014 postreply 19:08:08

• 別忙著下結論。車禍受傷是因為保險帶沒拉住人，氣囊沒擋住頭，還是車身形變引起的？我看後者可能性大些。那樣的話，經撞是很重要的。 -周老大- ♂ (0 bytes) () 10/07/2014 postreply 21:19:05

• What a funny logic -CW62- ♂ (694 bytes) () 10/08/2014 postreply 07:14:35

• you don't even know under what condition CM holds true -MoonRiverMe- ♂ (515 bytes) () 10/08/2014 postreply 16:37:57

• Are you serious? -CW62- ♂ (447 bytes) () 10/09/2014 postreply 07:42:18

• 他在同一個問題中用同一個Vf表達兩個完全不用的量 -MoonRiverMe- ♂ (83 bytes) () 10/07/2014 postreply 15:41:05

• 仔細看看，Vf一直是velocity after collision，怎麽表達兩個完全不同的量了？ -CW62- ♂ (0 bytes) () 10/07/2014 postreply 17:54:31

• 不要和閱讀能力有問題的較真啦，叫他自生自滅去吧～～ -修volvo- ♂ (0 bytes) () 10/11/2014 postreply 19:54:39