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EQ: How can the phenomena of reflection, refraction, interference, and diffraction be explained?

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Refraction of Light

What happens to light when it passes from one medium to another medium?

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16-4-1 Refraction of Light

Light waves bend, or refract, when they pass from one transparent medium to another because the speed of light differs in each medium.

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Refraction

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16-4-2 Refraction of Light, continued

• When light moves from a material in which its speed is higher to a material in which its speed is lower, the ray is bent toward the normal.

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16-4-3 Refraction of Light, continued

• If light moves from a material in which its speed is lower to one in which its speed is higher, the ray is bent away from the normal.

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16-4-4 Refraction of Light, continued

• Refraction makes objects appear to be in different positions.

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Refraction

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Lenses

What happens when light passes through a lens?

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16-4-5 Lenses

• lens: a transparent object with a curved surface that refracts light waves such that they converge or diverge to create an image

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16-4-6 Lenses, continued

• A converging lens bends light inward creating either a virtual image or a real image.

• .

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16-4-7 Lenses, continued

• A diverging lens bends light outward creating a virtual image.

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16-4-8 Lenses, continued

•Magnifying glasses in microscopes and refracting telescopes are examples of converging lenses.

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16-4-9 Lenses, continued

•By adjusting the height of the lens, you can focus the light rays together into a small area, called the focal point.

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16-4-10 Lenses, continued

• In the eye light first enters the cornea, then the pupil, then the lens, and then forms an image on the retina which contains light sensitive rods and cones.

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16-4-11 Lenses, continued

•Muscles can adjust the curvature of the lens until an image is focused on the back layer of the eye, the retina.

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The Eye

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Visual Concept: Parts of the Human Eye

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Dispersion and Prisms

How can a prism separate white light into colors?

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16-4-12 Dispersion and Prisms

A prism can separate the colors of light because the speeds of light waves traveling through the medium depend on the wavelengths of light.

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16-4-13 Dispersion and Prisms

• prism: in optics, a system that consists of two or more plane surfaces of a transparent solid at an angle with each other

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16-4-14 Dispersion and Prisms, continued

• Shorter wavelengths travel slower and are bent or diffracted more than longer wavelengths that travel faster and are refracted less.

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16-4-15 Dispersion and Prisms, continued• dispersion: the process of

separating a wave (such as white light) of different frequencies into its individual component waves (the different colors)