Light Intensity

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Eliana Carney 3E
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Light Intensity

Postby Eliana Carney 3E » Sun Oct 18, 2020 12:50 am

Just to clarify, when talking about increasing the light intensity during the photoelectric experiment, the scientists were just increasing the brightness of the light? They weren't changing the frequency/wavelength of the light?

Namratha Gujje
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Re: Light Intensity

Postby Namratha Gujje » Sun Oct 18, 2020 1:31 am

I believe so! The light is only getting brighter, it is not changing its frequency/wavelength.

Jasmine Ho 3I
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Re: Light Intensity

Postby Jasmine Ho 3I » Sun Oct 18, 2020 2:51 am

Yes, the intensity of light is related to the number of photons! More photons = brighter light

Charmaine Ng 2D
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Re: Light Intensity

Postby Charmaine Ng 2D » Sun Oct 18, 2020 2:55 am

Yep! They were just increasing the brightness of the light, only increasing the number of photons and not changing the frequency/wavelength, which is how they figured out that it wasn't working! That's when they realized that changing frequency is actually what allows them to cross the threshold energy :))

Rajshree 1F
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Re: Light Intensity

Postby Rajshree 1F » Sun Oct 18, 2020 10:10 am

Yes! The scientists hypothesized that making the light brighter would give the electrons more energy however increasing the number of photons (aka brightness) had no such effect but increasing frequency did.

Jarrett Sung 3B
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Re: Light Intensity

Postby Jarrett Sung 3B » Sun Oct 18, 2020 2:22 pm

Yup! When they increase the intensity of the light they are increasing the number of photons, which doesn't end up changing the energy, so in the photoelectric experiment the intensity change didn't increase the electrons released. This was how they realized the frequency changes the energy of the photons.

605291562
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Re: Light Intensity

Postby 605291562 » Sun Oct 18, 2020 2:49 pm

Yes! Like everyone else has said they adjusted the brightness. I believe if they would have increased the wavelength there would have been a change.

Helena Hu 3E
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Re: Light Intensity

Postby Helena Hu 3E » Sun Oct 18, 2020 2:51 pm

I would think that a greater amplitude of a light wave would mean higher intensity, as well. Hope this helps!

josephspindler2H
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Re: Light Intensity

Postby josephspindler2H » Sun Oct 18, 2020 2:59 pm

Yes, you are correct! If they had changed the wavelength or frequency, they would have changed the type of light being shown. As many have already stated, increasing the intensity led to an increase in total photons rather than individual photon energy. This is a problem on the quantum level where an individual photon must have enough energy rather than the whole system, thus frequency must be changed.

Megan Lu 3D
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Re: Light Intensity

Postby Megan Lu 3D » Sun Oct 18, 2020 3:24 pm

Hi! Yes, I believe that it was only the brightness (intensity) of the light that was increasing, not the actual frequency/wavelength.

Linette Choi 3L
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Re: Light Intensity

Postby Linette Choi 3L » Sun Oct 18, 2020 6:15 pm

Yup! Increasing the light intensity would just mean the light is getting brighter and the number of photons in increasing but it would not change the frequency or energy of the individual photon where it would have enough energy to eject an electron.

Gicelle Rubin 1E
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Re: Light Intensity

Postby Gicelle Rubin 1E » Sun Oct 18, 2020 6:20 pm

Hi there! You are correct, the wavelength/frequency did not change. It is the photons that affect the brightness of light, so it increased.

Irene Nguyen 2J
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Re: Light Intensity

Postby Irene Nguyen 2J » Sun Oct 18, 2020 6:25 pm

Yes, frequency and wavelength remain unchanged! Brighter light means there's an increase of photons.

Serena Song 1A
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Re: Light Intensity

Postby Serena Song 1A » Sun Oct 18, 2020 7:26 pm

Yup! The number of photons increases when the brightness increases, but the wavelength/frequency of each photon remains the same. If the wavelength/frequency changed, then that could've changed what type of EM wave it was instead (ex. from visible light to UV light if the frequency increased/wavelength decreased).

Susan Chamling 1F
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Re: Light Intensity

Postby Susan Chamling 1F » Sun Oct 18, 2020 7:36 pm

You're correct, the brighter light was caused by an increase in photons. For the experiment they realized that increasing the intensity of the light did not change the energy of the photons, because it is a change in wavelength/frequency that causes that change.

Gustavo_Chavez_1K
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Re: Light Intensity

Postby Gustavo_Chavez_1K » Sun Oct 18, 2020 9:32 pm

Exactly! So the experiment was basically just them changing the intensity of the light, so making it brighter. This is why they noticed that the electrons were not being ejected. However, once they changed the type of light, so the frequency, that is when the electron were ejected.

Danielle DIS2L
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Re: Light Intensity

Postby Danielle DIS2L » Sun Oct 18, 2020 9:58 pm

Increasing the light intensity would just increase the number of photons but not increase the frequency.

Nick Saeedi 1I
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Re: Light Intensity

Postby Nick Saeedi 1I » Sun Oct 18, 2020 9:59 pm

Yes. They were only increasing the amount of photons which is the intensity not the frequency of light.

Ayesha Aslam-Mir 3C
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Re: Light Intensity

Postby Ayesha Aslam-Mir 3C » Mon Oct 19, 2020 12:55 am

Only slightly related I suppose, but if the intensity of light is increased, I imagine the wave model would have higher peaks, correct? I thought the height of the peaks and the distance between them (wavelenght) correlated? So then light doesn't act in the wave form because the greater intensity indicates they do not correlate?

Sejal Parsi 3K
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Re: Light Intensity

Postby Sejal Parsi 3K » Mon Oct 19, 2020 3:16 am

Hey! That’s correct, increasing the intensity of the light meant increasing the brightness which is more photons. Had they increased the frequency/changed the wavelength, the experiment would have worked.

905290504
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Re: Light Intensity

Postby 905290504 » Mon Oct 19, 2020 12:41 pm

increasing intensity of light means increasing the number of photons which does make the light brighter. the important point here is that the energy of the indivudal photons doesn't change just the number of them

Annika Tamaki 1E
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Re: Light Intensity

Postby Annika Tamaki 1E » Mon Oct 19, 2020 12:43 pm

The intensity of the light refers to the number of photons, and results in no changes to the wavelength or frequency.

Gabriel Nitro 1E
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Re: Light Intensity

Postby Gabriel Nitro 1E » Mon Oct 19, 2020 1:03 pm

Hi,

Yes! As the intensity of the light increases, we associate that property as increasing in brightness! However, don't forget increasing intensity increases the number of photons!

For example, let's say we have two intensities and , where > . Thus, would have more photons than that of .

Hope this helps! :)

SamanthaTolentino 3D
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Re: Light Intensity

Postby SamanthaTolentino 3D » Mon Oct 19, 2020 1:08 pm

Increasing the intensity of the light meant increasing the amount of photons being aimed at the metal. Professor Lavelle gave an example with cross country runners and how increasing the intensity of runners meant increasing the number of runners.


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