My textbook states without proof that p, the momentum transferred by a wave onto a perfect absorber (normal incidence), is U/ c, where U is the total energy delivered in some time interval.(adsbygoogle = window.adsbygoogle || []).push({});

Is there a simple proof for this? Just something to help me rationalize. I tried equating kinetic energy to U. Then I set mv equal to p. But what I get is 2U/c, which is the p for a perfect reflector.

Any help is greatly appreciated.

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# Homework Help: Radiation momentum

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