Why doesn't the Spring Force change on splitting?

In summary, when a spring of spring constant K and length L is split into two parts L1 and L2, with spring constants K1 and K2 respectively, the spring force F remains unchanged and is equal to K1*L1=K2*L2=K*L. This can be explained by considering the springs as hypothetical blocks connected to each other and applying Newton's 3rd Law.
  • #1
navneet9431
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Suppose a spring of spring constant=K and Length=L is split into two parts L1 and L2, with spring constants K1 and K2 respectively.

Then,why is it such that the spring force F=K1*L1=K2*L2=K*L?

Please give an intuitive explanation of why the spring force doesn't change?

I will be thankful for help!
 
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  • #2
If I understand correctly, you asking why all those forces are equal in the case we have two springs connected in series.

Lets focus on spring with constant ##K_2##. To this spring are connected the spring with constant ##K_1## and the block (whose displacement is ##L=L_1+L_2## from the equilibrium position)
We can view the spring with constant ##K_1## as another hypothetical block connected to spring ##K_2##. Hence the force that the spring ##K_2## applies to this hypothetical block is by hook's law equal to $$F_{21}=K_2L_2 (1)$$.
By Newton's 3rd law the hypothetical block applies to the spring ##K_2## a force opposite and equal $$F_{12}=F_{21} (2)$$.

Now we focus on spring ##K_1##. To this spring is connected the spring ##K_2## which also can be viewed as a hypothetical block connected to spring ##K_1##. The force applied from spring ##K_1## to this hypothetical block is essentially the force ##F_{12}## and by hook's law it is equal $$F_{12}=K_1L_1 (3)$$
By combining (1) (2) and (3) we get that ##K_1L_1=K_2L_2##.

Maybe my explanation is not very intuitive but I don't see any other way how we can prove it, without viewing the springs as hypothetical blocks and also have to use Newtons 3rd Law.
 

1. Why doesn't the Spring Force change on splitting?

According to Hooke's Law, the force exerted by a spring is directly proportional to its extension or compression. When a spring is split, its length remains the same, therefore the force it exerts also remains unchanged.

2. Does the material of the spring affect the Spring Force on splitting?

No, the material of the spring does not affect the Spring Force on splitting. As long as the spring maintains its length, the force it exerts will remain the same.

3. What happens to the Spring Force if the spring is split into multiple pieces?

The Spring Force is divided equally among the different pieces of the spring. Each piece will exert a smaller force compared to the original spring but the overall force will remain the same.

4. Can the Spring Force change in any other scenario besides splitting?

Yes, the Spring Force can change in other scenarios such as changing the material or length of the spring, or applying an external force on the spring. These changes will alter the spring's stiffness and affect the force it exerts.

5. Is there a limit to the number of times a spring can be split before the Spring Force changes?

As long as the spring maintains its original length, there is no limit to the number of times it can be split before the Spring Force changes. However, if the spring is stretched or compressed beyond its elastic limit, it will permanently change the Spring Force.

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