Waves, Sound, and EM Waves

Sound Example of compressional wave Can travel through any type of matter Speed of sound depends on the substance the medium is made of and whether it is solid, liquid, or gas In solids, particles are closer together so particles can transmit energy more quickly Travel fastest in solids and slowest in gas

Sound Speed of sound in air = 347 m/s As the temperature of a substance increases, its molecules move faster so sound waves move faster

Reflection Reflection = Bouncing back of waves Angle of Incidence equals Angle of Reflection

Refraction – bending of waves

Diffraction – spreading of a wave

Electromagnetic Spectrum

Made of vibrating electric charges and can travel through space where matter is not present Energy transferred by vibrating electric and magnetic fields Speed of light m/s Fastest in gases and slowest in solids

Radio Waves –AM radio waves, FM radio waves, Television Microwaves –Used in communication and heating foods Infrared Waves –Thermal energy –Hotter objects give off more IR waves than colder objects

Visible Light Detected with eye Colors –ROY G BIV –Red-Orange-Yellow Green Blue-Indigo-Violet Shortest wavelength – Blue Longest wavelength – Red

Gamma Rays Ultraviolet Waves –Useful in killing bacteria in objects X-rays –Can take images of organs, tissue, and teeth Gamma Rays –Used in radiation therapy