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Light wave = EM waves. Dont req a medium to propagage!!! (i think qualitatively a fundamental difference for different properties)
Sound Wave= Mechanical Wave, Requires a medium. In sound, the velocity is dependent on the medium in which it travels. The change is simply the ratio of V=(Elastic component/Inertial Component)^1/2.. In order to keep velocity of wave constant, the frequency increases as the wavelength decreases (which makes sense, the no of wavelengths that pass through a particular point will increase in a given time, only if the wavelength decreases; ie the distance between the crests decreases). The rule to remember is velocity is constant in a particular medium and depends only on the property of the media. Its independent of amplitude, frequency and wavelength.
Now my question, when sound wave goes from air to water, the frequency and wavelength changes or no? The velocity is dictated by the medium, so it will change based on that property, but how about the frequency and wavelength?
EM waves; E=hf (Energy is proportional to the frequency)
I think of EM as independent of medium and hence when they actually enter any media besides air, they will slow down (myway of thinking, I read in one of the threads that the velocity remains constant, but the time it takes to cross a medium with a higher index of refraction is greater will slows down light) Energy of light is constant, when it undergoes simultaneous refraction and reflection, since half of the photons perform each function and energy is conserved. As the index of refraction increases, the velocity decreases, the wavelength decreases, but the frequency is constant. Now the index of refraction, n=C/V; C is a constant, so n increases, v must decrease, which is inline with my intuitive way of thinking about velocity.
If we are looking at the prism, the red light has a higher wavelength and thus must have a greater velocity to keep the lower frequency ( compared to other waves) constant ( what I dont understand is when we write R=V/I; R is an idependent variable, but as current in a conductor increases, the voltage usually decreases, so why we use the same analogy here with less say greater wavelength, lower velocity???) Additionally, to keep the velocity (C=nV) constant, as velocity of red light increases, its index of refraction is lower and sin of the angle will be higher, ie the theta is close to 90...or closer to the normal.This ensures that snells law is obeyed.
I want to be sure that everything i wrote here is correct.
Sound Wave= Mechanical Wave, Requires a medium. In sound, the velocity is dependent on the medium in which it travels. The change is simply the ratio of V=(Elastic component/Inertial Component)^1/2.. In order to keep velocity of wave constant, the frequency increases as the wavelength decreases (which makes sense, the no of wavelengths that pass through a particular point will increase in a given time, only if the wavelength decreases; ie the distance between the crests decreases). The rule to remember is velocity is constant in a particular medium and depends only on the property of the media. Its independent of amplitude, frequency and wavelength.
Now my question, when sound wave goes from air to water, the frequency and wavelength changes or no? The velocity is dictated by the medium, so it will change based on that property, but how about the frequency and wavelength?
EM waves; E=hf (Energy is proportional to the frequency)
I think of EM as independent of medium and hence when they actually enter any media besides air, they will slow down (myway of thinking, I read in one of the threads that the velocity remains constant, but the time it takes to cross a medium with a higher index of refraction is greater will slows down light) Energy of light is constant, when it undergoes simultaneous refraction and reflection, since half of the photons perform each function and energy is conserved. As the index of refraction increases, the velocity decreases, the wavelength decreases, but the frequency is constant. Now the index of refraction, n=C/V; C is a constant, so n increases, v must decrease, which is inline with my intuitive way of thinking about velocity.
If we are looking at the prism, the red light has a higher wavelength and thus must have a greater velocity to keep the lower frequency ( compared to other waves) constant ( what I dont understand is when we write R=V/I; R is an idependent variable, but as current in a conductor increases, the voltage usually decreases, so why we use the same analogy here with less say greater wavelength, lower velocity???) Additionally, to keep the velocity (C=nV) constant, as velocity of red light increases, its index of refraction is lower and sin of the angle will be higher, ie the theta is close to 90...or closer to the normal.This ensures that snells law is obeyed.
I want to be sure that everything i wrote here is correct.
