P4.d - Ultrasound 0.0 / 5 ? PhysicsWavesGCSEOCR Created by: simonhwCreated on: 25-01-16 13:04 How is sound produced? Vibrating particles that form a wave. 1 of 16 What is wavelength? The distance between two successive points on the wave having the same displacement and moving in the same direction. 2 of 16 What kind of waves are sound and ultrasound waves? Longitudinal waves. 3 of 16 What does rarefaction refer to? The part of the wave where air particles are spread out. 4 of 16 What does compression refer to? The part of the wave where air particles are compressed. 5 of 16 Why can't longitudinal waves be heard in space? They cannot travel through vacuums. 6 of 16 What is frequency? The number of complete waves in a second. 7 of 16 What is frequency measured in? Hertz (Hz). 8 of 16 Higher pitch and smaller wavelengths are all a consequence of what? A higher frequency. 9 of 16 What is the upper threshold of human hearing? 20 000Hz 10 of 16 What happens at the centre of compression and the centre of rarefaction. With compression, the pressure is greater than when no wave is present. It is the same for rarefaction, but the pressure is very small. 11 of 16 What do pressure waves have to exist in? A medium. 12 of 16 Why do sound waves travel faster in water than air? Water is a denser medium. 13 of 16 What is different about the vibrations of particles in transverse waves? They are at right angles to the direction of the wave. 14 of 16 What is amplitude? The maximum distance a particle moves from its normal position. 15 of 16 More energy in a wave and larger amplitudes are a consequence of what? Louder sound waves and more powerful ultrasound waves. 16 of 16
Comments
No comments have yet been made