Sound Waves

A. What Causes Sound 1. It is produced by an object that vibrates. 2. Depends on the collisions of particles to transfer energy through a medium Tuning Fork

B. Type of wave 1.Are compressional waves a. compressions and rarefactions b. need a medium

C. Moving Through a Medium 1.Sound travels best in solids why? a. because the molecules are closer together they can transmit the energy from one to another more rapidly 2.Loud sounds travel at the same speed as soft sounds why? a. because loudness deals with the amount of energy carried 3. Sound travels faster through warm temperatures because the molecules are moving faster and are more likely to collide.

Moving Through a Medium

D. INTENSITY 1.Amount of energy a wave has corresponds to its amplitude 2.For compressional waves it is related to the density of the particles in a compression and rarefaction

Intensity 3. INTENSITY: the amount of energy that flows through a certain area in a specific amount of time a. when you turn down the volume on your radio you are reducing the energy carried by the sound waves b. influences how far the sound wave will travel

E. Loudness 1. human perception of sound intensity (decibel, dB) 2. Sound waves with high intensity carry more energy 3. As the intensity of a sound wave increases, the loudness of the sound wave also increases

F. PITCH 1. Frequency: how many wavelengths pass a certain point each second. 2. Pitch: how low or how high a sound seems to be: directly related to frequency C D EF G A B C do re mifa so la ti do Hz

G. Doppler Effect 1. change in pitch or wave frequency due to a moving wave source.