6 Wave SpeedThe speed of a wave will depend on the medium it travels throughThe state of matter determines the speed of the wave.EX: In gases the particles are spread out so the wave travels slower in gasesEX: In liquids, the particles are closer together so the energy is transferred quicker between particles of that mediumEX: In solids, the particles are tightly packed together so the wave travels very quickly through solids
8 Doppler Effect – Occurs when the wave source is moving. Image SimulationBreaking the sound barrier
9 Light Waves Light waves occur in different frequencies and wavelengths Light waves are represented on the electromagnetic spectrumThe Electromagnetic Spectrum consists of visible light and other waves that cannot be seen.
12 The Electromagnetic Spectrum Consists of light at all possible energies, frequencies, and wavelengths.Visible light is only a small part of the spectrum.The spectrum also contains X-rays, Ultraviolet rays, Radio Waves, Gamma waves.
13 The Nature of Light Light acts as a wave in that it: produces interference patterns like water wavesFollows the laws of reflection, diffraction, and refraction
14 The Nature of Light Light also acts as a particle These particles are called PHOTONSA beam of light is considered to be a stream of photons.Photons do not have mass…they are like “bundles of energy”
15 Light Wave SpeedAll electromagnetic waves in empty space travel at the same speedThe speed of light is: 3.00 x 108 m/s or 186,000 miles/secondLight will travel slower when it has to pass through a medium such as air or water
24 Wave InteractionsWaves may interact with each other when traveling through a mediumThere are 3 possible outcomes:Reflection, Diffraction, and Refraction
25 1. DiffractionA change in the direction of a wave when the wave finds an obstacle or an edge
26 2. ReflectionThe bouncing back of a wave when the wave hits a surface or boundary
27 Reflection of light Every object reflects some light Rough surfaces reflect light in many directionsSmooth surfaces reflect light in one direction
28 Law of ReflectionWhen light hits a smooth surface, the angle of incidence equals the angle of reflection.
29 3. RefractionThe bending of waves when they pass from one medium to anotherCauses the wave to bendPrism Example:
30 Laws of RefractionWhen light travels in a medium with a higher speed to a medium where it slows down, the ray is bent toward the normal
31 Laws of RefractionWhen light travels from a medium where it is slower to a medium where it can travel faster, light bends away from the normal
32 RefractionBecause of refraction images appear to be in different positions
33 Wave Absorption Energy from the wave is absorbed into the medium Often as heat (measured as thermal energy).
34 Thermal Energy Thermal conductors have a high rate of energy transfer Thermal insulators have a slow rate of thermal energy transferRate of thermal energy transfer is dependent on temperature, color, texture and exposed surface area of the object.
35 Thermal EquilibriumThe amount of thermal energy absorbed is equal to the amount of thermal energy emitted.The temperature remains constant.