A box with two springs on a frictionless table

AI Thread Summary
The discussion revolves around a physics problem involving a box on a frictionless table with two springs attached at either end. The main confusion arises from how the applied force compresses both springs simultaneously, despite one being compressed and the other stretched as the box moves. Participants clarify that the correct force is 2N and the displacement is 3cm, not 30cm, which affects the calculation of the spring constant. There is also a debate about whether the forces from the two springs cancel each other out, prompting a closer examination of the direction of the forces involved. Understanding the forces' directions is crucial for solving the problem correctly.
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Homework Statement


upload_2016-10-17_21-22-10.png


Homework Equations

The Attempt at a Solution


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I'm having trouble visualizing what is going on in this problem. I imagine that the box is in a position like this with a spring on each end of the box. Then a force F is applied that compresses the springs. What I'm wondering is: How does the force parallel to the springs compresses both springs? It would seem that one would be compressed, while the other would not be effected.
upload_2016-10-17_21-26-45.png
 

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The springs are attached to the box, so if the box moves, the attached ends of the springs move with it. The outer ends of the springs are clamped to some fixed supports. So when the box moves, one spring is compressed while the other is stretched.
 
gneill said:
The springs are attached to the box, so if the box moves, the attached ends of the springs move with it. The outer ends of the springs are clamped to some fixed supports. So when the box moves, one spring is compressed while the other is stretched.
So more like this? Where the black rectangles are the supports?

upload_2016-10-17_21-37-39.png
 
Yup. Here's my version:

upload_2016-10-17_21-40-13.png
 
Hi, going back to this. Wouldn't the spring constant just be 2.6N/.3m? Making it 8.66 N/m? Why is this wrong, do I need to take into account another spring?
 
CRobinson said:
Hi, going back to this. Wouldn't the spring constant just be 2.6N/.3m? Making it 8.66 N/m? Why is this wrong, do I need to take into account another spring?
1. The force is 2N, not 2.6N
2. The displacement is 3cm., not 30cm.
3. There are two springs. What force does each exert?
 
I need more clarification on this; there's only one force and one distance unit for the motion of two springs, would those two springs traveling in opposite directions not cancel out? I've tried the difference and the sum, nothing is right.
 
dgood said:
I need more clarification on this; there's only one force and one distance unit for the motion of two springs, would those two springs traveling in opposite directions not cancel out? I've tried the difference and the sum, nothing is right.

Look at the drawing in #4. In what direction is the force from the left spring that is compressed? What about the force from the right spring that is stretched? This should tell you whether the forces cancel out.
 
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