Energy of Wave: Does Amplitude Affect E?

[jaumzaum]

Is there a equation that calculate the energy of a wave acccording to the amplitude

Another question, The plank equation E = h.f calculate the energy of any wave according to the frequency? If so, why doesn't the amplitude affect the energy (in the equation)?

 

[Drakkith]

Plank's equation is only applicable to an Electromagnetic wave. IE Light. It was discovered that the energy per "wave" was only related to frequency of the light. As for WHY amplitude doesn't matter, that is complicated and beyond my knowledge.

 

[Freeze3018]

Einstein's showed that (in his 1905 papers) light is made up of photons and each photon's energy depends on its frequency.
energy of 1 photon is h.f

 

[nasu]

Is there a equation that calculate the energy of a wave acccording to the amplitude

Another question, The plank equation E = h.f calculate the energy of any wave according to the frequency? If so, why doesn't the amplitude affect the energy (in the equation)?

There are various formulas, depending on the type of the wave (EM, sound, etc). The "energy of the wave" is not a very well defined quantity. You may want to look at energy density, the energy in a specific unit volume, if it's a standing wave. Or maybe the energy flux, the energy transported by a progressive wave through a specific area in unit time.
In general these quantities depend on both the amplitude of the wave and frequency.

Now going to the quantum picture, the Plank formula gives the minimum energy (photon) that the wave may transport, exchange, etc. The total energy density or flux depends on the number of photons in the wave which can be related to the (classical) amplitude of the wave.

 

[PJC01]

I can confirm that the amplitude of a wave does indeed affect its energy. In fact, the energy of a wave is directly proportional to the square of its amplitude. This relationship can be expressed mathematically as:

Energy ∝ amplitude^2

This means that as the amplitude of a wave increases, its energy also increases. This is because the amplitude represents the maximum displacement of the wave from its equilibrium position, and the greater the displacement, the more energy is required to create and sustain the wave.

Regarding the second question, the Plank equation (E = h*f) does calculate the energy of a wave based on its frequency. This equation is specifically used for electromagnetic waves, where the frequency (f) represents the number of wave cycles per second and Planck's constant (h) is a fundamental constant of nature. The amplitude of the wave does not affect the energy in this equation because it is already taken into account through the frequency. As the frequency increases, the energy of the wave also increases, regardless of the amplitude.

In summary, both the amplitude and frequency of a wave play a role in determining its energy. The specific equations used to calculate energy may vary depending on the type of wave, but they all take into account the relationship between amplitude, frequency, and energy.