Electromagnetic Waves

Front

Electromagnetic Wave Noun

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[eh-lek-tro-mag-net-ik wayv]

Back

Electromagnetic Wave

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A wave consisting of vibrating electric and magnetic fields that can transfer energy through empty space.

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Example: An electromagnetic wave consists of an electric field and a magnetic field oscillating at right angles to each other and to the direction of travel.

Front

Mechanical Wave Noun

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[meh-kan-i-kuhl wayv]

Back

Mechanical Wave

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A wave that requires a medium, which is matter, to travel through and transfer its energy.

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Example: This diagram shows a transverse wave moving through water, a medium. It labels the wave's highest point (crest), lowest point (trough), length, and height.

Front

Medium Noun

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[mee-dee-uhm]

Back

Medium

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The matter or substance through which a wave can travel to transfer energy.

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Example: This diagram labels the parts of a transverse wave, like crest and wavelength, but does not illustrate a medium, the substance a wave travels through.

Front

Transverse Wave Noun

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[trans-vurs wayv]

Back

Transverse Wave

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A wave in which the particles of the medium move perpendicular to the direction that the wave travels.

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Example: This diagram shows a transverse wave, labeling its highest point (peak), lowest point (trough), height from the center (amplitude), and the wavelength.

Front

Magnetic Field Noun

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[mag-net-ik feeld]

Back

Magnetic Field

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An area of magnetic force that surrounds a magnet or a moving electric charge.

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Example: This diagram shows the invisible magnetic field around a bar magnet. The lines, flowing from the North (N) to the South (S) pole, represent the field's direction.

Front

Electric Field Noun

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[eh-lek-trik feeld]

Back

Electric Field

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An area of electrical force that exists around a charged particle.

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Example: An electric field is a region around a charged particle. The field lines, shown by arrows, point away from a positive charge and towards a negative charge.

Front

Electromagnetic Radiation Noun

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[eh-lek-tro-mag-net-ik ray-dee-ay-shun]

Back

Electromagnetic Radiation

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The transfer of energy from one place to another by means of electromagnetic waves.

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Example: This diagram shows the electromagnetic spectrum, a range of energy waves from long radio waves to short gamma rays, including the visible light we see.

Front

Reflect Verb

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[ri-flekt]

Back

Reflect

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To bounce back from a surface that a wave cannot pass through.

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Example: An electromagnetic wave, like light from a flashlight, bounces off a surface like a mirror. The angle it hits (incidence) equals the angle it bounces off (reflection).

Front

Refract Verb

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[ri-frakt]

Back

Refract

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To bend as a wave passes at an angle from one medium into another.

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Example: When a light wave passes from one medium (like air) to another (like water), it bends or changes direction, which is called refraction.

Front

Diffract Verb

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[di-frakt]

Back

Diffract

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To spread out as a wave moves around an obstacle or passes through an opening.

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Example: When a wave, such as a light wave, passes through a narrow opening or around an obstacle, it bends and spreads out.