# Homework Help: Colision question

## physics in flight school

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1. Feb 7, 2004

### nodnarb

a 1g car going 5 m/s on a frictionless track colides with another car that weights 2.5g and is motionless after the colision the cars stay together what forces are keeping them together

i need someone to respond to this so i can print it out and show my teacher that i actually loged on to this site [?]

2. Feb 7, 2004

### HallsofIvy

Okay, print this out and show it to your teacher:

Why in the world did you choose to post a poll? Especially when you don't have a "poll" question. I have to choose to check either "Do you use physics in flight" or "How are you"????

"a 1g car going 5 m/s on a frictionless track colides with another car that weights 2.5g and is motionless after the colision the cars stay together what forces are keeping them together "
(Have they told you about question marks in school yet?)

I have no idea what forces are keeping them together and the information given in that question certainly won't tell me. I could calculate their common speed after the collision (it is 1/7 m/s) but there is no way to know "what forces are keeping them together".

Since I can also calculate that if this were a perfectly elastic collision, the smaller car would rebound sharply, this is not an elastic collision. Perhaps the two cars got locked together in the collision, perhaps there was glue on one or both cars! There is no way to know WHAT is holding them together.

To the teacher: This is an excellent place for students to post questions about their homework. People responding to posts are very good about giving hints without simply doing the homework themselves.
It is NOT a good idea to post things just for the sake of posting!

Last edited by a moderator: Feb 7, 2004
3. Feb 7, 2004

### nodnarb

confused

i have a lab to do and i was not there ro do it and was trying to remember all of the variables on it so im sorry if that question seemed a little on the bizare side but that was all the info that i could think of

is there anything that you might think is missing besides the glue[zz)]