Presentation on theme: "Properties and Characteristics"— Presentation transcript:
1Properties and Characteristics EM NOTESProperties and Characteristics
2What do we know about EM waves in general? They are ALL Energy—Radiation!Non-mechanical Transverse wavesThey do not need a medium—travel in space!!Have crests/troughsThey all travel at the speed of light(300,000 km/sec) in space!Fastest: Space…air…water…solid: slowestMost are not visible by the human eye!
4How are EM waves Different? They have differentFrequenciesWavelengthsAmounts of energyThese characteristics impact some of their properties and behavior!
5ROY G. BIV One EM Example: The EM wave we can detect (see) Visible LightThe EM wave we can detect (see)It is WHITE = blend of all colorsROY G. BIV(Red, Orange, Yellow, Green, Blue, Indigo, Violet)Different due to wavelength and frequency
6Wave BehaviorEM waves behave a certain way when they hit a material. They may possibly…Reflect—bounce offAbsorb – held within = heatTransmit- travel through
7ReflectionWaves bounce (reflect) off of a surface at the same angle that they hit the surface at.Mirror
9Reflection Sound can be reflected also = Echo Other real-life examples…A submarine periscopeGames dealing with angles!Ping pong, basketball, poolSound can be reflected also = Echo
10Absorption & Reflection Why do we see certain colors?Different frequencies of light are “absorbed” or “reflected”What we see = reflected to our eyes
11Absorption & Reflection Red Truck is red because…Truck absorbs all light waves except redred is reflected back to our eyesDo you wear a white or black shirt in the summer?If all light is absorbed = BLACK = HotterIf all light is reflected = WHITE = Cooler
12Absorption & Reflection Black clothes absorb more light energy = HEAT!!!Avoid black in summersWear black in winters
13Waves Transmitted Waves travel through an object/material Not reflected or absorbedWhat two things will determine if a wave transmits through?The waves energy and The mediumWhen they travel through they may…1. Refract OR 2. Disperse or Diffract
14Refraction waves change speeds as they move through different mediums. Changing speeds causes Waves To Bend!Wave going in(Water)Wave refracted
15RefractionExample:Where is the fish actually at if you are fishing using the diagram? WHY?
16RefractionExample:Where is the fish actually at if you are fishing using the diagram? WHY?The fish is actually further than what the man will see.Actual fish
17Dispersion / Diffraction When white light passes through a prism or slit it bends causing the colors to separate so you can see them.What causes a rainbow?raindrops cause the light to disperse