https://padlet.com/12158414/g0549zjt26q Donald Bullock en-us 2016-12-19 18:24:46 UTC 2025-12-02 13:15:59 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Planets.png 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144366854 When we think of the word "wave" we usually picture someone moving their hand back and forth to say hello or maybe we think of a tall curling wall of water moving in from the ocean to crash on the beach.]]> 2016-12-19 18:30:54 UTC https://padlet.com/12158414/g0549zjt26q/wish/144366854 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144367069 Mechanical waves are waves that require a medium. This means that they have to have some sort of matter to travel through. These waves travel when molecules in the medium collide with each other passing on energy. One example of a mechanical wave is sound. Sound can travel through air, water, or solids, but it can't travel through a vacuum. It needs the medium to help it travel. Other examples include water waves, seismic waves, and waves traveling through a spring. 

]]> 2016-12-19 18:31:55 UTC https://padlet.com/12158414/g0549zjt26q/wish/144367069 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144367181 Electromagnetic waves are waves that can travel through a vacuum (empty space). They don't need a medium or matter. They travel through electrical and magnetic fields that are generated by charged particles. Examples of electromagnetic waves include light, microwaves, radio waves, and X-rays. 


]]> 2016-12-19 18:32:25 UTC https://padlet.com/12158414/g0549zjt26q/wish/144367181 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144367819
Transverse waves are waves where the disturbance moves perpendicular to the direction of the wave. ]]> 2016-12-19 18:35:18 UTC https://padlet.com/12158414/g0549zjt26q/wish/144367819 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144368879
Longitudinal waves are waves where the disturbance moves in the same direction as the wave.]]> 2016-12-19 18:40:22 UTC https://padlet.com/12158414/g0549zjt26q/wish/144368879 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144369619
The wavelength of a wave is the distance between two corresponding points on back-to-back cycles of a wave. This can be measured between two crests of a wave or two troughs of a wave. The wavelength is usually represented in physics by the Greek letter lambda (λ). ]]> 2016-12-19 18:43:56 UTC https://padlet.com/12158414/g0549zjt26q/wish/144369619 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144507954 The frequency of a wave is the number of times per second that the wave cycles. Frequency is measured in Hertz or cycles per second. The frequency is often represented by the lower case "f." 


]]> 2016-12-20 18:07:47 UTC https://padlet.com/12158414/g0549zjt26q/wish/144507954 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144508168 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. ]]> 2016-12-20 18:08:51 UTC https://padlet.com/12158414/g0549zjt26q/wish/144508168 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144508874 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.]]> 2016-12-20 18:13:12 UTC https://padlet.com/12158414/g0549zjt26q/wish/144508874 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144509088 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! ]]> 2016-12-20 18:14:27 UTC https://padlet.com/12158414/g0549zjt26q/wish/144509088 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144509278 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. ]]> 2016-12-20 18:15:30 UTC https://padlet.com/12158414/g0549zjt26q/wish/144509278 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144509572 2016-12-20 18:16:52 UTC https://padlet.com/12158414/g0549zjt26q/wish/144509572 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144510396 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. ]]> 2016-12-20 18:21:56 UTC https://padlet.com/12158414/g0549zjt26q/wish/144510396 12158414 https://padlet.com/12158414/g0549zjt26q/wish/144511421 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.]]> 2016-12-20 18:28:46 UTC https://padlet.com/12158414/g0549zjt26q/wish/144511421