How will the car 3 move?

VietDao29

Hi,
I am not an native English speaker, so please forgive me if I have any mistakes. I am in grade 10th.
I cannot use the lab without permission, and anyway, I don't think that the teacher will let me use it just on my own. So I cannot immagine what will happen in the following cases: (Giving that there's no friction force):
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1. Picture 1a shows 3 cars. Car 3 on the right side of car 1, and car 2 on top of car 1, conecting with each other by a small cord (wieghtless).
Giving that the car 2 is moving forwards.
The car 1 will move backwards. How will the car 3 move. Will it touch the car 1's side like in picture 1b or will it be like picture 1c?
2. And how will the car 3 move if one of the side of the cord is sticked to the wall (Picture 2)? Will it move like picture 1b or 1c?
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Can you please help me.
I appreciate any help.
Thanks very much,

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