Sound & vibration
THE SPEED OF SOUND
Sound waves travel at different speeds through different mediums. When we talk about “the speed of sound” we’re referring to our most common reference point, which is how quickly sounds travel through the air.
■ In dry air of 0°C, sound waves travel at 331 metres per second (m/s).
■ In water, they move at 1,481m/s
■ In a solid, like iron, they travel at 5,120m/s. That’s faster than Usain Bolt when he ran his world-record-breaking 10,44m/s in the 100m race!
DANIEL Kish has been blind since he was 13 months old. However, he moves around independently with ease – scaling mountains and cycling without help. He is one of a handful of blind human echolocators and shares this gift with animals like bats, dolphins and
