Physics Help: Calculating Speed for a Sled Collision Test Tomorrow

[Pytagoras]

Basic physics, need some help :D

Hi, first i would like to start of by saying that i am norwegian, so my english skills is not so good. But anyway, I am having this test tomorrow and i need some help! Its about physics! I translated the task as good as i could!

To sleds with elastic bumpers collides with each other on a air-cussion course. Sled A's mass is 0,1kg, and sled b's mass is 0,4 kg. After the impact, sled A is moving at 0,5m/s and sled B is standing still. Calculate the speed of the to sleds before the impact.

Thanks for all answears!
If something is badly explained, please let me know!

 

[siddharth]

Because it's given that the bumpers are elastic, I guess you should assume that the collision is elastic.

Can you tell me what principle or concept you should apply here? For example, what can you say about the energy and momentum of the sleds?

 

[Pytagoras]

I seriousy don't know, that's the task, i have no more info that that.
I don't have a clue how i should do this :(

 

[siddharth]

I don't have a clue how i should do this :(

Yes, but you should try to figure out what principles you should apply by yourself.
Try using the hint I gave you on my last post about the energy and momentum of the two sleds.

 

[Pytagoras]

Okay, I am doing this for a friend, so me myself as i said have no clue :D
Thanks for the help so far :D