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Light travels nearly a million times faster than sound.
True
What is the speed of light in a vacuum?
Light travels faster than sound.
True
When light passes from one medium to another, the bending of light is known as ______.
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What is the Law of Reflection?
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Match the following properties with light:
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Study Notes
Characteristics of Light
- Light is the electromagnetic radiation that enables vision
- Light travels at a speed of approximately 186,281 miles (300,000 kilometers) per second in a vacuum
- Light travels nearly a million times faster than sound
Definition and Speed of Light
- Light is a form of electromagnetic radiation that enables vision, traveling at approximately 186,281 miles (300,000 kilometers) per second in a vacuum.
- Light travels nearly a million times faster than sound.
Sources of Light
- Luminous objects emit light from within, such as stars, the sun, the moon, electric lights, and fires.
- Illuminated objects reflect externally supplied light.
Properties and Sources of Light
- Light travels extremely fast and far, carries energy and information, bounces and bends when in contact with objects, and has color and different intensities.
- Light carries energy and power, with intensity referring to the amount of energy per second falling on a surface.
Refraction and Reflection of Light
Refraction
- Refraction occurs when light rays bend as they cross a boundary from one material to another, like from air to water.
- Examples of refraction include light rays from a straw being refracted when they cross from water back into air before reaching the eyes.
Reflection
- The Law of Reflection states that the angle of incidence equals the angle of reflection.
How Light Travels
- Light rays travel in straight lines from the light source.
- When hitting an opaque object, some light is absorbed, and the rest is reflected.
Color and Vision
- Combining all the colors of the rainbow results in white light, with different colors attributed to varying kinetic energies.
- The human eye sees color based on the amount of energy the light possesses.
Dispersion and Prisms
- When white light passes through a glass prism, blue is bent more than red, due to the variation in refractive index with color, known as dispersion.
- A rainbow is a natural example of dispersion, where tiny rain droplets act as prisms, separating the colors in white light rays from the sun.
How the Human Eye Sees Color
- The retina in the back of the eye contains photoreceptors, which release chemical signals determining the color we perceive.
- Chemical signals, based on the energy of light, travel to the brain along the optic nerve.
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Description
Test your knowledge of light's properties, including its speed and electromagnetic nature. Learn about the fascinating characteristics of light in this quiz.
