SOUND

Sound Sound is a form of energy that is produced and transmitted by vibrating matter. A vibration is a back and forth motion.

Sound A wave is a disturbance that transfers energy from place to place. A compression wave is made by sound, it moves energy outward from its source.

Sound Compressions: parts of the wave where particles are closer together Rarefactions: parts of the wave where particles are spread out

Sound Medium: material through which sound waves travel (solids, liquids, or gases) Sound must have a medium in order to travel, no medium = no sound

Why can the sound below not be heard?

Sound Sound travels the quickest through solids Sound travels the slowest through gases

Which of the following does sound travel through the quickest? How do you know that sound travels the quickest through this substance?

Frequency Frequency is the number of vibrations in a given unit of time It is measured in Hertz

Pitch Pitch describes how high or low a sound is It is determined be frequency Objects vibrating faster have a higher pitch Objects vibrating slower have a lower pitch

Which one do you think produces a higher pitch? The large tuba or the smaller trumpet? Which one has a higher frequency? How do you know?

Which one do you think has the most vibrations per second? The smaller string or the fatter string? What does that mean about the pitch of each?

Wavelength Measures the distance between one compression to the next The longer the wavelength the less frequency. The shorter the wavelength the more frequency.

Which wave has a greater wavelength? What does the wavelength mean for the frequency of the wave?

Amplitude Amplitude is the height of a wave Higher amplitude = louder sound Lower amplitude = softer sound

Volume Volume is how loud or soft a sound is more energy makes a louder sound Less energy makes a softer sound Volume is measured in decibels If amplitude increase volume increase

Which part of the wave has a higher amplitude? What does that mean about the wave’s volume?