The speed of light
Light travels extremely quickly. Its maximum speed is approximately 300,000,000 m/s, when it travels through a vacuum.The very large difference between the speed of light in air (almost 300,000,000 m/s) and the speed of sound in air (343 m/s) explains why you:
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Light
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is visible to the human eye and is responsible for the sense of sight. Light travels as transverse waves and faster than sound. It can be reflected, refracted and dispersed. Ray diagrams show what happens to light in mirrors and lenses. Eyes and cameras detect light. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space). They do not need a substance to travel through, but they can travel through transparent and translucent substances. |
ReflectionLight waves reflect from surfaces. The angle of incidence equals the angle of reflection.
Smooth surfaces produce strong echoes then sound waves hit them, and they can act as mirrors when light waves hit them. The waves are reflected uniformly and light can form images. Rough surfaces scatter sound and light in all directions. However, each tiny bit of the surface still follows the rule that the angle of incidence equals the angle of reflection. Reflection is when light bounces off an object. If the surface is smooth and shiny, like glass, water or polished metal, the light will reflect at the same angle as it hit the surface. This is called specular reflection.
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RefractionLight waves change speed when they pass across the boundary between two substances with different densities, such as air and glass. This causes them to change direction and this effect is called refraction. We can use water waves in a ripple tank to show this effect.
Refraction doesn't happen if the waves cross the boundary at an angle of 90° (called the normal) - in this case, they carry straight on. The refraction follows a regular pattern. When light passes from air into a block of glass the following is seen: Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media
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Our experiments on lightThese are just some pictures from the experiments we did. All the experiments are related to light and how we can use light to do multiple different things and ways in photography. We did this experiments to try and understand how light works and how we can use it. We had to try and work out how to use the correct aperture, ISO and shutter speed for a good picture. We used different angles to get different pictures and we used colour papers to change the colours of the light to make the picture more interesting for the viewer.
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