- #1
hello478
- 165
- 14
- Homework Statement
- image below
- Relevant Equations
- energy equations
My attempt:
my answer was b
correct answer is d
Question about the energy of 2 blocks with a spring between them
Click For Summary
Homework Help Overview
The discussion revolves around the energy dynamics of two blocks with a spring between them, specifically focusing on kinetic energy and conservation principles in the context of elastic collisions.
Discussion Character
- Exploratory, Conceptual clarification, Assumption checking
Approaches and Questions Raised
- Participants explore the concept of kinetic energy, questioning the assumptions around conservation and the implications of blocks being stationary before release. There are discussions about the expression for kinetic energy and its relevance to the problem.
Discussion Status
The conversation includes attempts to clarify misunderstandings about kinetic energy and conservation principles. Some participants suggest that a deeper understanding of the underlying theory is necessary, while others express challenges in grasping the concepts despite familiarity with the textbook material.
Contextual Notes
Participants mention constraints such as time limitations due to upcoming exams and the challenges of studying independently without classmates for support.
My attempt:
my answer was b
correct answer is d
- #2
BvU
Science Advisor
Homework Helper
- 16,219
- 4,933
Can you explain why you picked b ?
Do you know the expression for kinetic energy?
Do you know the expression for kinetic energy?
- #3
hello478
- 165
- 14
because before the release they are stationaryBvU said:
and it is elastic collision, maybe...
so the kinetic energies would add upto 0
so that the total KE is conserved...
- #4
- 15,897
- 9,064
"Conserved" means "it is the same" throughout whatever is going on. Before release the sum of kinetic energies is zero because neither block is moving. If, as you claim, this sum is conserved, then neither block should be moving after release. Do you think that is the case?hello478 said:
- #5
- 22,823
- 14,864
Why would kinetic energy be conserved? This would mean the blocks just remain stationary as kinetic energy is non-negative.hello478 said:
- #6
BvU
Science Advisor
Homework Helper
- 16,219
- 4,933
BvU said:
- #7
hello478
- 165
- 14
1/2 mv2
- #8
hello478
- 165
- 14
oh ok so, the velocities direction would not be considered.... thats the only thing i understand uptill now
- #9
- 22,823
- 14,864
It sounds to me that based upon your many posts with seemingly little thought behind your attempts that what you really need to do before attempting these problems is to sit down with your book and try to understand the theory behind the problems first. Otherwise you will just be shooting wildly with your answers.hello478 said:
- #10
hello478
- 165
- 14
ill try to do that, though i sort of know what the book says... physics is just not my thing so its difficult for me to graspOrodruin said:
when i read the book, everything is so easy until the questions blow my mind...
- #11
- 22,823
- 14,864
Sort of know typically won’t do. You need to actually know and most of all understand what it says. Work through any derivations so that you understand where things come from, do the same with any examples. Go equation by equation and make sure you understamd how and why it came about.
- #12
BvU
Science Advisor
Homework Helper
- 16,219
- 4,933
Tip (that worked for me): while reading, invent tough exercises you could test your classmates with.hello478 said:
Re 'not my thing': seems to me math isn't either. But systematic reasoning and logical thinking are indispensable in all fields! (what's yours?)
##\ ##
- #13
hello478
- 165
- 14
ok ill try to do that too, but i dont have much time till my exams...BvU said:
and im a private student
so... i dont have classmates
and im currently doing physics AS levels and biology A levelsBvU said: