Understanding Head-On Collisions: Elastic vs. Inelastic & Impact of Mass Ratios

[fball558]

Head-on collision HELP!

Homework Statement

Consider a head-on collision between two objects. Object 1, which has mass m1, is initially in motion, and collides head-on with object 2, which has mass m2, and is initially at rest. Which of the following statements about the collision are true?

A. |P1,final| < |P1,initial|
B. If m2 >> m1, then |P1| > |P2| (last P's have deltas representing the change in P)
C. If m2 >> m1, then the final speed of object 1 is greater than the final speed of object 2.
D. If m1 >> m2, then the final speed of object 2 is less than the initial speed of object 1.
E. P1,initial = P1,final + P2,final

There can be more than one answer.

i not sure what kind of collision this is (inelastic or elastic) i assumed elastic and got
A.
B.
C.
E.

not sure if this is right and only have one more attempt so want to make sure i understand what is going on. any help would be great!
thanks

 

[fball558]

i just tried it and the computer says they are wrong?
you have any idea why?
i guess i have one more attempt (thought the last one was my last attempt but i guess not)
here is everything i have tried (4 attempts)
1. ALL A B C D E
2. A B D
3. A B D E
4. A B C E

 

[rl.bhat]

D is also correct.

 

[fball558]

D is also correct.

so are you saying that they all are correct?
I already tired that (attempt #1)
that is what made sense to me, but still said i was wrong??

 

[fball558]

got the answer it is only
A. C. E.
i guess it is an elastic collision
thanks for the help

 

[tianbian]

Homework Statement

B. If m2 >> m1, then |P1| > |P2| (last P's have deltas representing the change in P)


I do not understand this sentence

p1 and p2 is the initial? or final?

and can you explain"last P's have deltas representing the change in P"
please tell me the detailed of this sentence.
I can't understand this sentence.
by the way I come form MARS.

 

[fball558]

Homework Statement

B. If m2 >> m1, then |P1| > |P2| (last P's have deltas representing the change in P)


I do not understand this sentence

p1 and p2 is the initial? or final?

and can you explain"last P's have deltas representing the change in P"
please tell me the detailed of this sentence.
I can't understand this sentence.
by the way I come form MARS.

what i mean when i say "the last P's have deltas representing the change in P)
i mean that the |P1| > |P2| is really change in momentom of P1 is greater than Change in momentom of P2.
so |P1| would really mean P1(final) - P1(inital) and same with |P2| just substitute P2 in place of P1.