https://padlet.com/12256105/ht96ngj6n01r Charlie Hedgepeth en-us 2016-12-19 16:32:11 UTC 2023-06-24 19:59:42 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Planets.png 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144343689 2016-12-19 16:40:03 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144343689 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144344089 A periodic disturbance of the particles of a substance that may be propagated without net movement of the particles, such as in the passage of undulating motion, heat, or sound.]]> 2016-12-19 16:41:46 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144344089 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144344618 A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, oscillating material does not move far from its initial equilibrium position. ]]> 2016-12-19 16:43:55 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144344618 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144345694 One of the waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity and that include radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays. ]]> 2016-12-19 16:48:05 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144345694 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144347025 A wave vibrating at right angles to the direction of its propagation. ]]> 2016-12-19 16:54:20 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144347025 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144347579 Longitudinal waves are waves where the disturbance moves in the same direction as the wave. One example of this is a wave moving through a stretched out slinky or spring. If you compress one portion of the slinky and let go, the wave will move left to right. At the same time, the disturbance (which is the coils of the springs moving), will also move left to right. Another classic example of a longitudinal wave is sound. As sound waves propagate through a medium, the molecules collide with each other in the same direction as the sound is moving. ]]> 2016-12-19 16:56:50 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144347579 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144348188 The distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave. ]]> 2016-12-19 16:59:26 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144348188 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144355595 In physics, the number of crests of a wave that move past a given point in a given unit of time. The most common unit of frequency is the hertz (Hz), corresponding to one crest per second. The frequency of a wave can be calculated by dividing the speed of the wave by the wavelength.]]> 2016-12-19 17:35:18 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144355595 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144355886 Radio waves have the longest wavelengths of all the electromagnetic waves. They range from around a foot long to several miles long. Radio waves are often used to transmit data and have been used for all sorts of applications including radio, satellites, radar, and computer networks. ]]> 2016-12-19 17:36:56 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144355886 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356036 Microwaves are shorter than radio waves with wavelengths measured in centimeters. We use microwaves to cook food, transmit information, and in radar that helps to predict the weather. Microwaves are useful in communication because they can penetrate clouds, smoke, and light rain. The universe is filled with cosmic microwave background radiation that scientists believe are clues to the origin of the universe they call the Big Bang. ]]> 2016-12-19 17:37:49 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356036 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356233 Between microwaves and visible light are infrared waves. Infrared waves are sometimes classified as "near" infrared and "far" infrared. Near infrared waves are the waves that are closer to visible light in wavelength. These are the infrared waves that are used in your TV remote to change channels. Far infrared waves are further away from visible light in wavelength. Far infrared waves are thermal and give off heat. Anything that gives off heat radiates infrared waves. This includes the human body.]]> 2016-12-19 17:38:49 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356233 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356338 The visible light spectrum covers the wavelengths that can be seen by the human eye. This is the range of wavelengths from 390 to 700 nm which corresponds to the frequencies 430-790 THz. You can go here to learn more about the visible spectrum. ]]> 2016-12-19 17:39:26 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356338 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356487 Ultraviolet waves have the next shortest wavelength after visible light. It is ultraviolet rays from the Sun that cause sunburns. We are protected from the Sun's ultraviolet rays by the ozone layer. Some insects, such as bumblebees, can see ultraviolet light. Ultraviolet light is used by powerful telescopes like the Hubble Space Telescope to see far away stars.]]> 2016-12-19 17:40:18 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356487 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356738 X-rays have even shorter wavelengths than ultraviolet rays. At this point in the electromagnetic spectrum, scientists begin to think of these rays more as particles than waves. X-rays were discovered by German scientist Wilhelm Roentgen. They can penetrate soft tissue like skin and muscle and are used to take X-ray pictures of bones in medicine. ]]> 2016-12-19 17:41:38 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356738 12256105 https://padlet.com/12256105/ht96ngj6n01r/wish/144356868 As the wavelengths of electromagnetic waves get shorter, their energy increases. Gamma rays are the shortest waves in the spectrum and, as a result, have the most energy. Gamma rays are sometimes used in treating cancer and in taking detailed images for diagnostic medicine. Gamma rays are produced in high energy nuclear explosions and supernovas. ]]> 2016-12-19 17:42:18 UTC https://padlet.com/12256105/ht96ngj6n01r/wish/144356868