• Support PF! Buy your school textbooks, materials and every day products Here!

Conservation of momentum + elastic collision

  • Thread starter Return
  • Start date
  • #1
13
0
[SOLVED] Conservation of momentum + elastic collision

Hey guys, I couldnt even start this one, tried to think about it, but I'm hitting a blank

A block of mass m = 2.20 [kg] slides down a 30 degrees incline which is 3.60 [m] high. At the bottom, it strikes a block of mass M = 7.00 [kg] which is at rest on a horizontal surface. (Assume a smooth transition at the bottom of the incline.) If the collision is elastic, and friction can be ignored, determine A) the speeds of the two blocks after the collision and B) how far back up the incline the smaller mass will go.


know: m = 2.20kg
theta = 30 degrees
h = 3.60m
M = 7.00 kg

Ok so I don't understand how to find the velocity when the blocks start. I know that the collision in elastic so momentum is conserved, but should I use conservation of energy or dynamics to solve for it?


Any help would be great. Thank you!
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,832
249
I know that the collision in elastic so momentum is conserved, but should I use conservation of energy or dynamics to solve for it?
Hi Return! :smile:

No … all collisions conserve momentum.

"elastic" means that energy is conserved also.

Does that help? :smile:
 
  • #3
13
0
lol oh yea, thats a slap in the head ty for the reminder

I got this one over lunch, so looks like I'm good, used a combination of conservation of momentum and conservation of energy.
 

Related Threads for: Conservation of momentum + elastic collision

Replies
27
Views
2K
Replies
2
Views
4K
Replies
3
Views
11K
Replies
1
Views
1K
Replies
3
Views
3K
Replies
3
Views
1K
Replies
15
Views
5K
Replies
6
Views
2K
Top