## Amplitude

$c=\lambda v$

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Ava_Basileo_2J
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Joined: Wed Sep 30, 2020 9:42 pm

### Amplitude

Is amplitude used only in the wave model? Also, does increasing amplitude increase the amount of energy of the light and thus brightness?

Neel Sharma 3F
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### Re: Amplitude

Yes, the amplitude is a feature of waves. Prof. Lavelle explained amplitude as the height of a wave in the ocean. A larger, taller wave has more energy as compared to a short, smaller one. Waves with large amplitudes have more energy and are brighter. Yet when we discuss the photoelectric effect, increasing the brightness and amplitude of the light was not ejecting electrons. Instead, it required a different type of light with a higher frequency to eject electrons. This relationship can be seen in the E = hv equation.

Nayra Gharpetian 3F
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### Re: Amplitude

yes amplitude is only used in the wave model. when light acts like a photon amplitude does not increase the energy. the only way to increase energy would be to increase frequency.

Ryan Hoang 1D
Posts: 95
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Amplitude

Neel Sharma 1G wrote:Yes, the amplitude is a feature of waves. Prof. Lavelle explained amplitude as the height of a wave in the ocean. A larger, taller wave has more energy as compared to a short, smaller one. Waves with large amplitudes have more energy and are brighter. Yet when we discuss the photoelectric effect, increasing the brightness and amplitude of the light was not ejecting electrons. Instead, it required a different type of light with a higher frequency to eject electrons. This relationship can be seen in the E = hv equation.

I think Neel's answer is great and is understandable. But, I just want to explain a bit more. Amplitude=intensity=the number of photons emitted in the photoelectric effect. Saying that there is more energy, while technically right, doesn't impact the photoelectric effect because the energy of ONE photon matters, not the energy of 100000 photons. Therefore, to increase the energy of one photon, we have to increase the frequency, or wavelength, which increases the energy of each photon that is emitted.

Joshua Chung 2D
Posts: 91
Joined: Wed Sep 30, 2020 9:32 pm

### Re: Amplitude

Yes, amplitude is specifically a feature of wave models. However, increasing the amplitude of a light source will not increase its energy - only its intensity. The only way (that's been mentioned in class so far) to change energy is to change frequency.

Ansh Patel 2I
Posts: 88
Joined: Wed Sep 30, 2020 9:42 pm

### Re: Amplitude

Hi! Yes, amplitude is part of the wave model, but increasing the amplitude does not increase the amount of energy of a photon. Rather, increasing the amplitude increases the number of photons, but the energy per photon remains the same.

Andrew Yoon 3L
Posts: 87
Joined: Wed Sep 30, 2020 9:36 pm

### Re: Amplitude

Amplitude is only used in the wave model. Increasing the amplitude means that there is a higher intensity. Decreasing the amplitude means that there is a lower intensity. With more a higher intensity, the brightness increases and vice versa. In order to change the energy, we have to change the frequency of the wave.

Joanna Huang
Posts: 87
Joined: Wed Sep 30, 2020 9:40 pm

### Re: Amplitude

Yep, amplitude is only used in the wave model. Increasing the amplitude does not increase the amount of energy, thus, regardless of the amplitude (aka number of electrons), each electron can only react with another electron, so increasing amplitude does not make the electron eject off easier.

Aria Movassaghi 1A
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Joined: Wed Sep 30, 2020 9:40 pm

### Re: Amplitude

Yes, it's only in the wave model

Lizbeth Garcia 1F
Posts: 87
Joined: Wed Sep 30, 2020 9:39 pm

### Re: Amplitude

It is only for wave models. The amplitude signifies the height of the wave. This determines the intensity of said wave which can be translated as brightness.

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