Fundamental Forces: Spring Question

In summary, the equation to calculate the force from a spring is ma=-k1l-k2l, with the positive direction defined as to the right. The change in length is not taken as an absolute value in this calculation.
  • #1
JoeyBob
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Homework Statement
See attached
Relevant Equations
F=lk
ma=-k2l+k1l

(ma-k1l)/l=-k

(-65.12-35.7)/0.51=-k

k=197.69, but answer should be 57.7
 

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  • #2
Sorry i had some wrong posts here which i deleted... Your mistake is in first line, you take one force as positive and the other as negative. Aren't both forces towards the same direction at position l?
 
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  • #3
Delta2 said:
Sorry i had some wrong posts here which i deleted... Your mistake is in first line, you take one force as positive and the other as negative. Aren't both forces towards the same direction at position l?

Okay I found out how to do it but am a bit confused. To get the right answer it needs to be

(-ma-lk)/l

This would mean the equation is ma=-k1l-k2l

But doesn't this imply the forces are in the negative i hat direction when they should be in the positive direction??
 
  • #4
On your picture which is the positive i hat direction? Is that the direction of the force when l is positive?
 
  • #5
hutchphd said:
On your picture which is the positive i hat direction? Is that the direction of the force when l is positive?
It would be to the right, no?
 
  • #6
So you have to define positive x (you have called it l) in that direction also. Going to the left is negative.
 
  • #7
hutchphd said:
So you have to define positive x (you have called it l) in that direction also. Going to the left is negative.

Isnt the change in length an absolute value though when calculating the force?
 
  • #8
No. The force from a spring is opposite from displacement. Hence the minus sign in ##F_x=-kx##.
 
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1. What are the fundamental forces in physics?

The four fundamental forces in physics are gravity, electromagnetism, strong nuclear force, and weak nuclear force. These forces govern the interactions between particles and objects in the universe.

2. How does the spring force work?

The spring force is a type of elastic force that occurs when a spring is stretched or compressed. It is caused by the deformation of the spring's material, which creates a restoring force that tries to return the spring to its original shape.

3. What is Hooke's law and how does it relate to springs?

Hooke's law is a principle that describes the relationship between the force applied to an elastic object and the resulting deformation. It states that the force is directly proportional to the displacement of the object. In the case of springs, this means that the force required to stretch or compress the spring is directly proportional to the distance it is stretched or compressed.

4. How do the fundamental forces affect the behavior of springs?

The fundamental forces play a role in determining the behavior of springs. Gravity, for example, affects the weight of an object attached to a spring, which in turn affects the amount of force needed to stretch or compress the spring. Electromagnetic forces can also impact the behavior of springs, as they can cause magnetic or electric fields that interact with the spring's material. However, the strong and weak nuclear forces are not typically involved in the behavior of springs.

5. How are the fundamental forces related to each other?

The four fundamental forces are believed to be related through a unified theory, although this theory has not yet been fully developed. Gravity and electromagnetism are thought to be related through the theory of general relativity, while the strong and weak nuclear forces are related through the theory of quantum mechanics. However, a unified theory that explains all four forces has yet to be discovered.

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