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Ch. 14 Waves and Energy Transfer. Milbank High School. Sec. 14.1 Wave Properties. Objectives Identify how waves transfer energy without transferring matter. Contrast transverse and longitudinal waves. Relate wave speed, wave-length, and frequency. Waves. Waves are everywhere!
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Ch. 14 Waves and Energy Transfer Milbank High School
Sec. 14.1 Wave Properties • Objectives • Identify how waves transfer energy without transferring matter. • Contrast transverse and longitudinal waves. • Relate wave speed, wave-length, and frequency.
Waves • Waves are everywhere! • Sound, light, radio, microwave, water, sine, cosine, telephone, earthquake, stadium, slinky… • Wave—rhythmic disturbance that carries energy through matter or space
Mechanical Waves • Require a medium • Water, air, ropes • Will not occur in a vacuum • Non-mechanical waves • Electromagnetic • light
Waves Con’t • Wave Pulse • Continuous Wave • Transverse Wave • Longitudinal Wave • Compressions and rarefactions
Surface Waves • Combination of both…(water)
Wavelengths • Crests • Troughs • Wavelength (λ) • Frequency f = 1/T • Hertz • Speed of wave v = λf Ex: Pg. 333
Sec. 14.2Wave Behavior • Objectives • Relate a wave’s speed to the medium in which the wave travels • Describe how waves are reflected and refracted at boundaries between media, and explain how waves diffract • Apply the principles of superposition to the phenomenon of interference
Wave Behavior • Waves can be reflected • Incident wave • Reflected wave • Sometimes passed on, sometimes reflected back, sometimes both
Superposition of Waves • Principle of superposition • A wave meets a reflected wave • Interference
Destructive Interference • Superposition of waves with equal but opposite amplitudes
Constructive Interference • Amplitudes are in the same direction • Creates a larger wave • Antinode • Node
Waves and Boundaries • Boundaries change speed and wavelength • Frequency stays the same • Type of barrier determines amount of change
Waves in two dimensions • Water waves • Reflection • Law of reflection • Angle of incidence = angle of reflection
Refraction of waves in two dimensions • Change in direction of waves at the boundary between two different media
Diffraction • Spreading of waves around a barrier • Water waves around a coral reef • Or more than one object • Interference would occur • Long wavelengths diffract the least • AM vs FM radio