What is Potential Energy? Learn About V=(1/2)*m*w2*x2

In summary, the equation gives the potential energy of a system that moves with simple harmonic motion.
  • #1
TooFastTim
13
0
Just reading up on lagrangeans and I came across an expression for potential energy I'd never seen before: V=(1/2)*m*w2*x2.

I suppose all you physics majors are familiar with it. But what is it and where can I find out more?
 
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  • #2
This looks like the equation giving the total energy of a system that moves with simple harmonic motion.
 
  • #3
TooFastTim said:
Just reading up on lagrangeans and I came across an expression for potential energy I'd never seen before: V=(1/2)*m*w2*x2.



Energy in a spring E=(1/2)kx^2

w=SQRT(k/m)
k = w^2m

E=(1/2)m(w^2)(x^2)

Yep. Simple harmonic oscilaror.

m = mass
w = angular frequency
x = maximum displacement / amplitude
 
  • #4
It it not the total energy, it is, as the OP suggests, the potential energy. The total energy of the harmonic oscillator must also include the kinetic energy.
 
  • #5
There is a continual interchange between PE and KE and the equation does give the total energy(ignoring damping).Expressing it another way it gives the maximum KE(when PE is zero) or the maximum PE(when KE is zero)
 
  • #6
Dadface said:
There is a continual interchange between PE and KE and the equation does give the total energy(ignoring damping).
The expression gives the total energy only when the kinetic energy vanishes, at the turning points. Damping is irrelevant to the issue. Even if damping is present, the expression still gives the total mechanical energy of the harmoic oscillator when and only when the kinetic energy vanishes, at the turning points. In general, the expression does not give the total energy.
 
  • #7
turin said:
The expression gives the total energy only when the kinetic energy vanishes, at the turning points. Damping is irrelevant to the issue. Even if damping is present, the expression still gives the total mechanical energy of the harmoic oscillator when and only when the kinetic energy vanishes, at the turning points. In general, the expression does not give the total energy.

Think of a simple pendulum,at the ends of the swing the bob has PE only and at the bottom it has KE only.At any other position it has a mixture of the two and if damping is negligible the PE plus KE remains constant.Similar reasoning can be applied to any other system that moves with SHM.
 
  • #8
Thanks guys.
 

What is potential energy?

Potential energy is the energy possessed by an object due to its position or configuration. It is a form of stored energy that can be converted into other forms, such as kinetic energy.

How is potential energy calculated?

The formula for potential energy is PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height of the object. Alternatively, for objects with a spring-like potential, the formula is PE = (1/2)*k*x^2, where k is the spring constant and x is the displacement from equilibrium.

What is the relationship between potential energy and kinetic energy?

Potential energy and kinetic energy are two forms of energy that are interchangeable. When an object gains potential energy, it loses kinetic energy, and vice versa. This is known as the law of conservation of energy.

How does potential energy relate to the formula V=(1/2)*m*w2*x2?

This formula is used to calculate the potential energy of an object with a spring-like potential, where V is the potential energy, m is the mass of the object, w is the angular frequency of the oscillation, and x is the amplitude of the oscillation.

What are some examples of potential energy?

Some examples of potential energy include a ball at the top of a hill, a stretched rubber band, a compressed spring, and a pendulum at its highest point. In each of these cases, the object has the potential to do work because of its position or configuration.

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