Elastic head-on collision

  • Thread starter Chica1975
  • Start date
  • #1
Chica1975
63
0

Homework Statement


a 5.00g object moving to the right at 20.0cm/s makes an elastic head-on collision with a 10.0g object that is initially at rest. Find the velocity of each object after the collision.


Homework Equations



p=mv
m1v1 +m2v2/m=m1=m2

The Attempt at a Solution


I have attempted this question several times.

I have converted all units to kg and m/s before starting all calculations.
I found the momentum for each using p=mv but this was not the right answer.
then I tried the other equation I have given and tried to minus the initial velocity from answer - still its not correct.

I am not great at collisions and find these really difficult - esp the conservation of energy/momentum concepts. I don't know to translate the conceptual into the application using equations and the info given in the question.

Please someone help me.
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,838
255
Hi Chica1975! :smile:
I have converted all units to kg and m/s before starting all calculations.
I found the momentum for each using p=mv but this was not the right answer.
then I tried the other equation I have given and tried to minus the initial velocity from answer - still its not correct.

I am not great at collisions and find these really difficult - esp the conservation of energy/momentum concepts. I don't know to translate the conceptual into the application using equations and the info given in the question.

In collisions, momentum is always conserved.

In collisions, energy is never conserved unless the question says so … in this case it does, because it uses the word "elastic".

You always need two equations to solve a collision question … one is always conservation of momentum, the other is either conservation of energy or some other constraint like "perfeclty inelastic" or " coefficient of restitution = 0.5".

So here you'll need both of the conservation equations …

show us your full calculations, and then we'll see what went wrong, and we'll know how to help! :smile:
 

Suggested for: Elastic head-on collision

  • Last Post
Replies
8
Views
522
Replies
20
Views
354
Replies
5
Views
294
Replies
6
Views
384
Replies
19
Views
646
Replies
10
Views
424
Replies
6
Views
303
Replies
16
Views
607
Replies
5
Views
344
Replies
7
Views
488
Top