SCIENCE EXAM: 2ND QUARTER

• Sounds are waves that carry energy
• Sound waves travel longitudinally and its speed is affected by different factors
• Dapple effect is the variation of the pitch heard from a moving source of sound
• Longitudinal waves travel through a medium (solid, liquid, and gas)
• Sound is produced in vibrating matter and moves in a back-and-forth motion along the medium uts travelling through
• Compression - series of pull
• Rarefaction - series of push
• Crest - highest peak of the wave
• Medium transmits the energy from the source sournce of sound. It can also be solid, liquid, or gas
• Trough - lowest peak of the wave
• Vibrating body - a source that is set into vibration by an external force
• Receiver - receiver of sounds (ear) through which sound is perceived
• Speed - distance travelled per unit time by a sound wave
• Wavelength - defined as the distance between two successive crests or troughs of a wave
• Period - the time required for one complete cycle of the wave to pass by a point. The time takes for two successive crests (one wavelength) to pass a specified point
• Density - the quality of having parts that are close together
• Speed of sound is affected by the density of materials
• Elasticity - refers to the tendency to maintain its shape and not deform when force is applied to it
• Elastic materials vibrate at lower speeds
• Rigid materials like steel vibrate rapidly when force is applied to it
• Temperature - sound travels faster if it is hot. As substance heats up, it molecules move faster so they collide move frequently
• Sound travels faster when the environment is warm
• Sound travels slower when the environment is cold
• Speed - sound is transmitted more easily through solids than through liquids and gases
• Frequency - is the number of vibration that sound produces per unit of time
• Pitch - highness or lowest of a tone
• Lower frequency - lower pitch
• Higher frequency - higher pitch
• Higher frequency - shorter wavelength
• Lower frequency - higher wavelength
• Intensity - magnitude of sound energy as it travels through a unit are
• Amplitude - the measure of the amount of energy of a sound wave
• Greater intensity - greater amplitude
• Lowe intensity - lower amplitude
• Power - measure of sonic energy per unit of time
• Quality - richness and fullness of sound
• Regular vibrations produce rich and pleasant sound
• Irregular vibrations create unpleasant sound
• Shock wave - this happens when the speed of sound source is greater than the speed of sound waves
• Sonography - detects object and determine sizes and distances