Reflection Reflection is the change in direction of a wave front at an interface between two different media so that the wave front returns into the medium from which it originatedwave interfacemedia

Refraction Refraction is the change in direction of a wave due to a change in its speed like when a wave passes from one medium to another. wave speed

Interference Interference is the addition (superposition) of two or more waves that result in a new wave pattern.superposition waves

Constructive Interference Constructive interference is when the troughs and peaks of 2 waves line up to make a bigger wave.

Destructive Interference Destructive interference is when the trough of one wave lines up with the crest of another wave. Generally there is no or little sound when this happens.

Wave Applications Microwaves are used for cooking and heating food. Infrared waves are used in heat lamps. Ultraviolet waves cause sunburn/skin cancer X-rays are used for medical diagnoses Gamma Rays are used in nuclear explosions.

Electromagnetic Spectrum The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. The electromagnetic spectrum of an object is the characteristic distribution of electromagnetic radiation from that object. electromagnetic radiation

Radio Waves Radio waves are located at one end of the electromagnetic spectrum. Located near microwaves and has the longest wavelengths.

Law of Conservation of Energy The Law of Conservation of Energy states that energy can’t be created nor destroyed….only changed from one form to another.

Problem If the velocity of the wave is 76 m/s and the frequency is 4. What is the wavelength? 76 = (4)( x) 4 19 = x

Problem If the frequency is 4 Hz and the wavelength is 11 m. What is the velocity? x = ( 4)(11) x = 44 m/s

Problem If the velocity is 60 m/s and the wavelength is 15 m. What is the frequency? 60 = (x)(15) 15 4 = x