16- Sound, Paper 2 (Section B) Flashcards
Fig 9.1 shows the wavefronts of a water wave in deep water in a ripple tank (16) Pg 1 (theory B)
The frequency of the wave in deep water is 5.0 Hz
(a) Explain what is meant by the frequency of a wave
(b) i) Determine the wavelength of the wave in deep water
ii) Calculate the speed of the wave in deep
(c) The wave passes from deep water into shallow water. The speed of the wave is less in shallower water.
i) State and explain how this affects the wavelength of the wave
ii) The wave in deep water shown in fig 9.2 travels towards the right and enters the shallow water at an angle. The wave refracts.
On fig 9.2 draw the wavefronts in the shallow water
(d) Sound is also a wave
i) Describe one difference between a sound wave and water wave
ii) The speed of sound in carbon dioxide gas is less than the speed of sound in air. Using this information or otherwise describe an experiment to show the refraction of the sound waves. You may include a diagram of your apparatus.
Both sound and ultrasound are waves that travels in solids, liquid and gases
(a) State how sound differs from ultrasound
(b) Sound and ultrasound are longitudinal waves that consists of compressions and rarefactions
i) Explain what is meant by a wave and description how a longitudinal wave differs from a transverse
ii) Fig 9.1 represents a longitudinal wave of a frequency 25 000 Hz travelling in oil (16) Pg 3 (theory B)
1. On fig 9.1 mark 2 point at the center of 2 different rarefaction and label each one R
2. On fig 9.1 draw a double-headed arrow to indicate a distance that is equal to one wavelength of the wave
3. Measure the length if the arrow drawn on fig 9.1 and use it to determine the speed of the wave in oil
(c) A sound wave traveling in liquid passes into air
i) State what happens to the speed of the sound wave as it enter the air
ii) The wave in the liquid travels towards the surface at angle. fig 9.2 shows the centers of the compressions of the sound wave in liquid
Some compressions shows have reached the liquid-air boundary. The parts of these compressions in the air are not show on fig 9.2
On fig 9.2 draw the parts of these compressions that are in the air
(d) Description in outline how ultrasound is used in cleaning
