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Physical Science
Chapter 12
| Answer | |
|---|---|
| Law of Reflection | The angle of reflection equals the angle of incidence |
| Reflection | Change in wave direction. When a wave encounters a barrier, it will reflect at an angle equal to the incoming angle. |
| Angle of Incidence | The angle of incoming ray |
| Angle of Reflection | The angle of the outgoing ray |
| Refraction | Bending or distortion in wave appearance/ behavior as a result of changing mediums. (objects in water appear distorted) |
| Rules of Refraction | 1.When light refracts into a substance where it must slow down, the light ray will bend toward a L _|_ to the surface it strikes.2.When light refracts into a substance where it speeds up, the light ray will bend away from a L_|_ to the surface it strikes |
| Diffraction | When waves encounter corners or obstructions, and bend and spread out a as a result |
| Wave length | Distance from crest to crest (or trough to trough) |
| Frequency | The number of wave crests that pass a given point each second. |
| Amplitude | the height of a wave, measured from the centerline of the wave to the top of a peak. |
| Crest | Highest point of a wave |
| Trough | Lowest point of a wave |
| Electromagnetic wave | A type of wave that does not need to travel through a medium. |
| Mechanical wave | A disturbance or variation which travels through a medium. The particles in the medium do not travel with the wave. |
| Longitudinal wave | The direction of propagation is parallel to its direction of oscillation. |
| Transverse wave | The direction of propagation (travel) is perpendicular to the direction of oscillation. |
| Supersonic speed | Any speed that is faster than the speed of sound in that particular substance |
| Mach | The speed jets can travel through the air Mach 1 = speed of sound in air (@25*C about 346 m/s) Mach 2 = twice the speed of sound in air |
| Sonic Boom | The sound produced when an object travels through air faster than Mach 1. |
| Pitch | A measure of how high or low a sound is. The frequency of a wave determines the pitch of the sound heard. |
| Speed of sound in air formula | v = 0.6(T)+331.5 m/sec V= speed of sound T = temperature in Celsius Units = m/sec |
| Basic function of our ears as it relates to sound waves | The tympanic membrane is a thin layer of tissue that is tightly stretched across the ear canal making a "drum" |
| How the speed of sound changes depending on the medium | The more dense the medium, the faster sound will travel. (ex: sound will travel faster in a solid than a liquid and a liquid faster than a gas) |
| Relationship between wavelength, frequency, and speed | Wavelength and frequency are inversely proportional. When wavelength increases, frequency decreases. The faster the wave, the higher pitched it will be. |
| Calculate relationship between wavelength, frequency, and speed | f=v/λ frequency=speed(velocity)/wavelength frequency is measured in Hertz (1/sec) |
| Basic function of our ears as it relates to sound waves (continued) | When the compressions from the sound waves hit the membrane, it vibrates and causes the bones and nerves of the inner ear to electrical signals to the brain. |
| Relationship between wavelength, frequency, and speed (continued) | (In the empty bottle , the sound waves travel all the way to the bottom of the bottle ....this means a wave with a LONG wavelength was formed. Since it had a LONG wavelength, the frequency was LOW Low frequency --> low-pitched sound) |