Sound and Waves

What this quiz asks

• Which unit is commonly used to express how loud a sound is?
• Which property of a sound wave mainly decides how high or low its pitch sounds?
• What is the unit of frequency, equal to one cycle per second?
• What is the name for sound pitched too high for humans to hear?
• What is the distance between one crest of a wave and the next called?
• Sound waves in air are longitudinal: the air vibrates back and forth along the direction the wave travels.
• Which land animal keeps in touch over several kilometres with rumbles too low for humans to hear?
• Does sound travel faster in warm air than in cold air?
• Dolphins echolocate with rapid clicks. Which part of the head focuses those clicks into a beam?
• Who became the first pilot to officially fly faster than sound, in 1947?
• Select ALL of these frequencies that a typical young person can hear.
• An increase of 10 decibels means a sound carries ten times as much energy.
• Select ALL of these animals that find their way or their food by echolocation.
• What is resonance?
• What produces the sonic boom heard when a jet flies faster than sound?
• Order these by how fast sound travels through them at room temperature, slowest first.
• About how fast does sound travel through seawater, in metres per second?
• The Mach number, used for speeds relative to sound, is named after which Austrian physicist?
• In 1845, how did Dutch scientist C. H. D. Buys Ballot test Christian Doppler's new theory of moving sound sources?
• Ultrasound probes make sound with crystals that vibrate when a voltage is applied. Which brothers discovered this piezoelectric effect in 1880?