SOUND SCIENCE GRADE 4
SCIENCE SUMMARY GRADE 4 TOPIC : SOUND Sound is produced by vibrations. Vibrations can be felt and seen. The volume or loudness of sound is measured in the unit decibels (db). The volume of sound can be measured using a sound level meter or a decibel meter. The louder the sound is, the higher its decibel rating. Sounds can travel through gases, liquids, and solid because the particles in solids, liquids and gases can pass on the vibrations. Sounds travel fastest through solids and slowest through gases. Sounds cannot travel through a vacuum as there are no particles to pass on vibrations. Vacuum is a volume of space without any matter. Outer space is a vacuum. Thus, sound cannot travel in outer space. We can reduce the loudness of sound using soft materials such as carpets, curtains and foam cushions. These materials can absorb some of the vibrations to reduce the loudness of the sound. We can prevent ear damage by wearing ear plugs or ...