Unit 3 Lesson 4- Sound and Hearing

1.  True or False: Sound can travel faster through air than it can through water or metal.  False. Sound can travel approximately 331 m/s through air; 1,509 m/s through fresh water; and 5,000 m/s depending on the type of metal it is traveling through.
2. True or False: Loudness is a subjective measurement, meaning it varies depending on who is hearing the sound. This is true. Loudness varies depending on the individual. Intensity, however, is the power of sound per unit area or the wave's energy in a unit area. This is not subjective, and it is measured in decibels.
3. True or False: High frequency sounds have a higher pitch, and low frequency sounds have a lower pitch. This is true. Although pitch can be subjective, it depends on frequency. If something has a high frequency, meaning something is vibrating quickly, it will have a higher pitch or sound like a higher note than something that is vibrating more slowly and has a lower pitch.

These properties can explain sound- 

speed, intensity, loudness, frequency, and pitch. 

Speed- You hear a delay in echoes because sound has speed and it takes time for these waves to travel. 

Sound waves travel fastest in solids, slowest in liquids, and slowest in gases. The speed of sound depends on many factor such as the density of the medium and how elastic the medium is.

Intensity- the rate at which a wave's energy flows through a given area. Sound intensity depends on both the wave's amplitude and the distance from the sound source. 

Loudness- a physical response to the intensity of a sound, modified by physical factors. 

Frequency depends on how fast the source is vibrating. 

Pitch- the frequency of the sound as you hear it

Ultrasound is sound at frequencies higher than most people hear. Sonar is a technique for determining the distance of an object underwater.