Derive conservation of mechanical energy for a simple spring.

In summary, starting with the equation of motion -kx = ma, integrating this with respect to x yields the equation for conservation of mechanical energy. However, the challenge lies in integrating the right hand side with respect to x. Using the Chain Rule, a can be expressed as a function of x and the integral of (mv dv) can be used to solve for the required answer.
  • #1
Narcol2000
25
0
Starting with the equation of motion -kx = ma , it is said that integrating this with respect to x gives the equation for conservation of mechanical energy.

Only problem is i don't see how to integrate the right hand side with respect to x...
 
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  • #2
Narcol2000 said:
Starting with the equation of motion -kx = ma , it is said that integrating this with respect to x gives the equation for conservation of mechanical energy.

Only problem is i don't see how to integrate the right hand side with respect to x...

Hi Narcol2000! :smile:

Hint: use the Chain Rule to get a as a function of x:

a = dv/dt = (dv/dx)(dx/dt) = … ? :smile:
 
  • #3
Turns into the integral of (mv dv) which gives the answer required... seems so easy looking back... :(

Thanks for your help.
 

1. What is the meaning of conservation of mechanical energy for a simple spring?

The conservation of mechanical energy for a simple spring refers to the principle that the total mechanical energy of a spring system remains constant, assuming there is no external force acting on the system. This means that the sum of kinetic and potential energies of the spring will remain the same over time.

2. How is the conservation of mechanical energy derived for a simple spring?

The conservation of mechanical energy for a simple spring can be derived using the equation E = 1/2kx^2, where E represents the total mechanical energy, k is the spring constant, and x is the displacement of the spring from its equilibrium position. By taking the derivative of this equation with respect to time, we can show that the rate of change of mechanical energy is equal to zero, indicating that the total mechanical energy remains constant.

3. What are the assumptions made when deriving conservation of mechanical energy for a simple spring?

The derivation of the conservation of mechanical energy for a simple spring assumes that there are no external forces acting on the system, and that the spring is massless and frictionless. It also assumes that the spring is in an ideal Hooke's law state, meaning that the restoring force is directly proportional to the displacement of the spring.

4. How is the conservation of mechanical energy applied in real-life situations?

The conservation of mechanical energy for a simple spring is applied in various real-life situations, such as in the design and analysis of mechanical systems like shock absorbers, car suspensions, and trampoline springs. It is also used in physics experiments to study the behavior of springs under different conditions.

5. Are there any limitations to the conservation of mechanical energy for a simple spring?

While the conservation of mechanical energy for a simple spring is a useful concept, it has its limitations. It only holds true in situations where there are no external forces acting on the system and where the spring is in an ideal state. In real-life situations, there may be external forces like friction and air resistance that can affect the energy of the system, making the conservation of mechanical energy more complex to apply.

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