1. Sound J.Sample 2014

2. Sound Sound is a form of energy produced and transmitted by vibrating matter. Sound must have a medium, (matter), to travel through. – Gasses, (air), liquids, or solids – Solids are fastest, molecules close together – Gasses are slowest, molecules farthest apart Sound cannot travel in a vacuum. – No medium to carry the waves.

3. Waves Sound waves are compression, (longitudinal) waves. – Molecules move backward and forward carrying the energy like a spring. – Some molecules are pressed together, compression – Some molecules are spread out, rarefaction

4. Frequency & Wavelength Wave length; the distance between two compressions or two rarefactions. – Measured from point to same point on two consecutive waves. Frequency is the number of wavelengths in a given unit of time. – Measured in hertz or cycles per second

5. Amplitude Amplitude is the amount of energy in a compression wave. – Related to intensity and volume – Loud sound many molecules with much force. – Soft sound fewer molecules with less force.

6. Pitch Pitch is determined by the frequency of a vibrating object. – Faster frequency, higher pitch, soprano – Lower pitch, slower frequency, bass As frequency changes so does pitch.

7. Sources Some animals can make and hear sounds different from those of humans. Musical instruments vibrate to produce sound. – Different instruments produce different vibrations in different ways. – Percussion; drums, symbols – Stringed; violin, piano, guitar – Wind; flute, clarinet, trumpet, trombone – Electronic; organ, keyboards, guitar

8. http://www.education.com/science- fair/article/sound-longitudinal-waves/