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Parbat
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When light enters into a denser medium,its velocity decreases.I can understand it is due to the optical density.But when the light again comes out of the denser medium,how does it regain its speed(i.e velocity of light).
Parbat said:if absorbing & re-emitting is the phenomenon,why isn't it possible without the direction change?(i mean refraction)
Drakkith said:I *believe* it is possible if the angle is perpendicular to the material. Like shining a laser pointer straight through a window. Since it isn't entering or leaving the material at an angle, there is no change in direction.
Frequency dispersion in groups of gravity waves on the surface of deep water. The red dot moves with the phase velocity, and the green dots propagate with the group velocity. In this deep-water case, the phase velocity is twice the group velocity. The red dot overtakes two green dots, when moving from the left to the right of the figure.
New waves seem to emerge at the back of a wave group, grow in amplitude until they are at the center of the group, and vanish at the wave group front.
For surface gravity waves, the water particle velocities are much smaller than the phase velocity, in most cases.
The velocity of light when it comes out of a denser medium depends on the refractive index of the medium. The refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. The higher the refractive index, the slower the speed of light will be in the medium.
Yes, the velocity of light changes when it passes through a denser medium. This is due to the interaction of light with the particles in the medium, which causes it to slow down.
The velocity of light in a denser medium is slower than the velocity of light in a vacuum. This is because in a vacuum, light encounters no particles and therefore travels at its maximum speed, while in a denser medium, light interacts with particles and is slowed down.
The change in velocity of light when it comes out of a denser medium is due to the change in the medium's refractive index. As light enters a denser medium, it interacts with more particles, causing it to slow down and therefore have a lower velocity when it exits the medium.
The velocity of light in a denser medium is directly related to the density of the medium. The denser the medium, the more particles light will encounter, causing it to slow down and have a lower velocity compared to a less dense medium.