How can we show mathematically that a wave transfers energy?

sanpokhrel · Sep 11, 2017

How can we show mathematically that a wave transfer energy?

berkeman · Sep 11, 2017

sanpokhrel said:

How can we show mathematically that a wave transfer energy?

Maxwell's equations and the Friis equation for antenna power transfer? https://en.wikipedia.org/wiki/Friis_transmission_equation

sanpokhrel · Sep 11, 2017

berkeman said:

Maxwell's equations and the Friis equation for antenna power transfer? https://en.wikipedia.org/wiki/Friis_transmission_equation

I just want a simple explanation. For a wave on a string, how can we show energy transfer.

Ibix · Sep 12, 2017

Look up "Feynman's sticky beads". Feynman used this (embarassingly simple) argument to show that gravitational waves carry energy. Modifying it for a mechanical wave is simple.

Drakkith · Sep 14, 2017

sanpokhrel said:

I just want a simple explanation.

I thought you wanted the math. If you want a simple explanation, never ask for the math behind something.

vanhees71 · Sep 14, 2017

On the other hand, explanations without math are either more complicated than with math or wrong.

How can we show mathematically that a wave transfers energy?

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