# Energy of a Wave: Amplitude vs Frequency

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• Lyakhnitskiy Dmitriy
In summary, the energy of a wave is related to its amplitude, but not to its frequency. This statement may vary depending on the type of wave and how other parameters are treated. According to Khan Academy, the energy of a mechanical wave does not depend on its frequency, but this may differ for electromagnetic waves. However, in mechanical waves, frequency does play a role in determining the energy it carries. This can be seen in the example of the photoelectric effect, where high frequency light is needed to extricate electrons from atoms, indicating a relationship between frequency and energy.f

#### Lyakhnitskiy Dmitriy

I need help with this question. The energy of wave related to its amplitude but not to frequency. If we talk about wave as disturbance carring energy we can imagine a swinging rope that gives potential energy to body by pushing it up. Bigger amplitude means getting high and increasing Potential energy of the body.
But bigger frequency means bigger amount of pushing the body up So the wave carries more energy.

P.S. Sorry for my bad English

The energy of wave related to its amplitude but not to frequency.
That depends on the type of wave, what you define as amplitude and the way you treat other parameters. Which wave do you mean and what is held constant?

That depends on the type of wave, what you define as amplitude and the way you treat other parameters. Which wave do you mean and what is held constant?
Amplitude is the biggest inclination from equilibrium position, I guess. Frequency is the number of occurrences of a repeating disturbance per unit of time. The thing is I got information about independency of energy of machenic wawe regarding to its frequency and wavelength from Khan Academy "Since the mediums are the same, we can focus on the wave energy increasing with the wave amplitude; not the frequency, wavelength or wave shape." But then I recognized photo effect when electrons need light of high frequency to be photo electrons. Electrons need more energy to be extricated from atom so is there depending between frequency and energy?

The energy of wave related to its amplitude but not to frequency.
The usual meaning for "the engergy of a wave" would be the "energy per unit time" it transmits. Perhaps you saw the statement that this energy does not depend on the frequency of wave in the context of electromagnetic waves.

In mechanical waves, the frequency matters. For example, http://spiff.rit.edu/classes/phys207/lectures/waves/wave_energy.html

Perhaps somebody can comment of whether this distinction between E&M versus mechanical waves is due to the absence of a material medium for E&M waves or whtether it is due to using two different definitions for "the energy of a wave".

Lyakhnitskiy Dmitriy