Download Waves and Sound: Properties, Terminology, and Physical Effects - Prof. Michael H. Ritzwoll and more Study notes Physics in PDF only on Docsity! 1 Phys 2010, Friday 4/20/07 Waves and Sound – Chapters 11-12 http://phet.colorado.edu ⇒ radio waves Waves carry information from one place to another Radio waves (electromagnetic - not sound!) Sound waves move through air Waves on the surface of water Particles behave as waves! Similar properties - amplitude, energy, and a wavelength that depends on frequency and speed. Propagate - to travel through space or a material. A wave "propagates" along the medium (A wave travels along the medium) Wave Terminology 1 Medium - The material that oscillates (bobs up and down). People, water, air (for sound waves), strings Medium does not move with the wave energy 2 Transverse wave - Medium oscillates perpendicular to direction wave travels. Waves on a string, light waves, radio waves, "The Wave" at a ball game Wave Terminology 2 Longitudinal waves - Medium oscillates parallel to direction wave travels. Sound, people jostling standing on a train, some slinkys Wave Terminology 3 Pulse - A single disturbance that propagates along the medium. Periodic wave - A disturbance that repeats itself over and over. A rope is wiggled like this: Which correctly shows the movement of point 1 on the rope as time progresses? A) B) 1 1 1 5 Physical Effects of Frequency - Color & Pitch Lower frequency Higher frequency Light Waves: Sound Waves: Lower frequency Higher frequency Bass Soprano UVIR Wave speed v units are meters/second. Frequency f units are cycles/second. Wavelength λ units are meters/cycle. Which relationship is correct? A) f = vλ B) λ = fv C) v = fλ D) f = λ/v Wave speed, v, depends on the medium that carries the wave. Frequency, f, depends on the rate of vibration of the source. Wavelength, λ, depends on speed and frequency. Which of these depend on the amplitude? A) v B) f C) λ D) None of these 6 A DC B E) Two or more points The oscillating string has potential and kinetic energy. At which point is the magnitude of potential energy maximum? Which point has maximum kinetic energy? Do points A and D have different kinetic energies? A) Yes B) No What do waves carry from one place to another? A) People B) Water C) Air molecules D) Energy/Information E) All of the above The graph shows a snapshot of a wave on a string traveling to the right. At the instant shown, the velocity of point P is in which direction? vwave P x A D B C E) None of these In which direction is the acceleration of P? 7 If all other conditions are the same, sound waves travel fastest when produced by which instrument? A) B) C) D) Same for all If all other conditions are the same, which instrument produces the highest frequency wave? A) B) C) D) Same for all If same medium, these waves travel at the same speed... …but a higher frequency produces a shorter wavelength.
