Sound Propagation in Science 8

SOUND Episode 3 SCIENCE 8 “Sound is an important means of communication for it allows the expression of our thoughts and feelings” SOUND Episode 3 SCIENCE 8 In which medium is sound likely to travel faster – through a sponge, rubber band or a piece of modeling clay? SOUND ¨ is...

SOUND Episode 3 SCIENCE 8 “Sound is an important means of communication for it allows the expression of our thoughts and feelings” SOUND Episode 3 SCIENCE 8 In which medium is sound likely to travel faster – through a sponge, rubber band or a piece of modeling clay? SOUND ¨ is a mechanical wave ¨ requires a medium to propagate and transmit energy from one point to another. SOUND FACTORS INFLUENCING PROPAGATION OF SOUND ¨Elasticity ¨Density ¨Temperature FACTORS INFLUENCING PROPAGATION OF SOUND Elasticity ¨Elastic medium allows particles to travel quickly. FACTORS INFLUENCING PROPAGATION OF SOUND Density Densed particles have minimal spaces ¨ allowing the sound to be transmitted easily from one particle to another. FACTORS INFLUENCING PROPAGATION OF SOUND Temperature Allows particles to move rapidly ¨ causing particles to collide more, resulting to faster propagation of sound FACTORS INFLUENCING PROPAGATION OF SOUND Temperature Speed of sound at 0 °C is ¨ equivalent to 331 m/s FACTORS INFLUENCING PROPAGATION OF SOUND Temperature ¨ Speed varies by a value of 0.6 m/s every degree Celsius change. ¨ Thus, calculation of speed of sound is: % % ! = 331 + (. 6 (/) & &/°- EXAMPLE 1: Let’s work with example problem page 72 number 1: A flash of lightning was seen in the sky, when the recorded temperature of the night was 22° C. Three seconds after the spark, a loud thunder was heard. What is the distance between the listener and the source of lightning and thunder? EXAMPLE 2: Find the wavelength in air at 20°C of an 18-Hz sound wave, which is one of the lowest frequencies that is detectable by the human ear. # != $