Conservation of Momentum and Energy in Elastic Collisions

  • Thread starter Thread starter mathewings
  • Start date Start date
AI Thread Summary
In the discussion on the conservation of momentum and energy in elastic collisions, a scenario is presented where a smaller package slides down a frictionless chute and collides with a larger stationary package. The initial calculation determines the common speed after the inelastic collision to be 0.865 m/s. The second part of the discussion addresses the elastic collision, where the user struggles to find the rebound height of the smaller package, consistently arriving at the original height of 2.44 m. Participants emphasize the need to apply both conservation of momentum and conservation of energy equations correctly to resolve the confusion. The conversation highlights the complexities of elastic collisions and the importance of accurate equation setup.
mathewings
Messages
8
Reaction score
0
A package of mass m is released from rest at a warehouse loading dock and slides down a 2.44 m high frictionless chute to a waiting truck. Unfortunately, the truck driver went on a break without having removed the previous package, of mass 7.00m, from the bottom of the chute. Suppose the packages stick together. What is their common speed after the collision?

Answer: 0.865 m/s

I solved this easily using kinematics to determine the small mass's velocity upon hitting the large mass. Then using conservation of momentum to isoalte the combined velocity. However, this secodn question confuses me:

Suppose the collision between the packages is elastic. To what height does the package of mass m rebound?

I've tried conservation of energy equations and always end up with a rebound to the original height of 2.44m. Can anyone offer suggestions?
 
Physics news on Phys.org
mathewings said:
I've tried conservation of energy equations and always end up with a rebound to the original height of 2.44m. Can anyone offer suggestions?
What makes you think your answer is incorrect?
 
How did you set up your conservation of energy equation for the collision? (You still need conservation of momentum as well.)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

A bullet collides perfectly elastically with one end of a rod
Replies
21
Views
2K
Speed of charged balls after collision
Replies
13
Views
1K
Elastic collision of particle and rotating disc
Replies
7
Views
2K
Why is momentum conservation always true in a collision?
Replies
4
Views
2K
Kinetic energy and momentum in an elastic collision
Replies
22
Views
3K
Ambiguous question on momentum and how it works...
Replies
13
Views
1K
How Does Angular Momentum Conservation Affect Asteroid Collision Dynamics?
7
Replies
335
Views
13K
What Height Does the Package Rebound to After a Perfectly Elastic Collision?
Replies
3
Views
19K
Physics Help with elastic collision
Replies
5
Views
2K
Solving Elastic Collision of Two Balls: Theory & Solutions
Replies
15
Views
3K

Hot Threads

Recent Insights

Back
Top