Energy and momentum imparted by an EM wave

In summary, when a plane electromagnetic wave is incident on a material surface, it delivers a momentum and energy. The correct statement is (4), where both the momentum and energy are not equal to zero. This is because the electric field component of the wave causes the electrons in the material to start moving, resulting in both momentum and energy.
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Titan97
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Homework Statement


A plane electromagnetic wave is incident on a material surface. The wave delivers a momentum ##p## and energy ##E##. Then which of the following is/are correct?

1) ##p=0,~E=0##
2) ##p\neq 0,~E=0##
3) ##p=0,~E\neq 0##
4) ##p\neq 0,~E\neq 0##

Homework Equations



None

The Attempt at a Solution


Is the answer (4)? When an em wave hits a surface, the electrons in it will start moving because of the electric field component. So it gets a momentum and some energy.
 
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Note:
If the question said that the wave delivers pizza P and Beer B then the correct statement would be ##P\neq 0, B\neq 0## ... it does not say how the wave delivers these things, perhaps it pushes a levitating train loaded with beer and pizza(?) - but that does not matter for the question as it is written.
 
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Related to Energy and momentum imparted by an EM wave

What is energy and momentum imparted by an EM wave?

The energy and momentum imparted by an electromagnetic (EM) wave refers to the transfer of energy and momentum from the wave to a particle or object that it interacts with. This can occur through various mechanisms, such as absorption, reflection, or refraction.

How is energy and momentum imparted by an EM wave measured?

The energy of an EM wave is typically measured in units of joules (J) or electron volts (eV), while the momentum is measured in units of kilograms times meters per second (kg·m/s) or electron volts per speed of light (eV/c). These measurements can be obtained through various experimental techniques, such as using a calorimeter to measure energy or a particle detector to measure momentum.

What factors affect the amount of energy and momentum imparted by an EM wave?

The amount of energy and momentum imparted by an EM wave depends on various factors, including the intensity of the wave, the frequency of the wave, and the properties of the material or object it interacts with. For example, a higher intensity EM wave will impart more energy and momentum than a lower intensity wave, and a higher frequency wave will impart more energy and momentum than a lower frequency wave.

How does the direction of an EM wave affect the energy and momentum imparted?

The direction of an EM wave can also affect the amount of energy and momentum imparted. When a wave is incident on an object perpendicular to its surface, the momentum transfer is maximized, while the energy transfer is minimized. Conversely, when a wave is incident at an angle to an object's surface, both the energy and momentum transfer will be reduced.

Can the energy and momentum imparted by an EM wave be controlled?

Yes, the energy and momentum imparted by an EM wave can be controlled through various means, such as changing the properties of the material or object it interacts with, or manipulating the characteristics of the wave itself. This is a key aspect in many technological applications, such as in communication systems, medical imaging, and energy harvesting devices.

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