Download Waves, Sound, and Light: Principles and Applications and more Study notes Physical education in PDF only on Docsity! Science Waves,Sound and Light Pulses: a single disturbance in a medium Principle of superposition: the algebraic sum of the altitudes of two pulses that occupied the same space at the same time. After each pulse passes through each other they continue in their original direction and size. Consecutive interference: when the crest of one pulse overlaps the other resulting in a larger pulse with an increased amplitude. Destructive interference: when the crest of one pulse overlaps the trough of another resulting in a smaller pulse of a decreased amplitude. Waves:a periodic, continuous disturbance that consists of a train of pulses. Transverse waves A wave in which the particles of the medium move or vibrate perpendicular to the direction of the motion of the wave. It doesn’t require a medium to travel and it moves up and down. Wavelength: the distance between two successive points that are in phase Wavespeed(v):the distance wave travels per unit time=meter per second(m.s) Frequency(f): the number of waves per second =Hertz(Hz) Period(T): time for one complete wave pulse.=seconds(s) • Frequency: f = T/1 • Period:T=f/1 • Speed:v=f·λ or v=Tλ. Longitudinal waves: a wave in which the particle of the medium vibrate parallel to the direction of the motion of the wave. Wavelength : distance between the centre of two successive compressions or two successive refractions. Requires a medium to travel. Same equations • Frequency: f = T/1 • Period:T=f/1 • Speed:v=f·λ or v=Tλ. Sound: are longitudinal waves that require a medium to travel because there are two factors which affect this medium’s speed. Density-sound travels faster in dense mediums due to particles being closely together therefore energy moves quicker and sound travels faster in a solid then a gas. Temperature-energy travels faster in mediums with a higher temperature since particles can move faster and pass energy because the kinetic energy is high. Unless otherwise stated the speed of sound in the air is taken to be 340 MS per second HEARING: THE HUMAN EAR IS DIVIDED INTO THREE MAIN SECTIONS: OUTER, MIDDLE, AND INNER EAR. STARTING WITH THE PINNA, IT COLLECTS AND FOCUSES SOUND WAVES, WHICH THEN TRAVEL THROUGH THE EAR CANAL TO MAKE THE EARDRUM VIBRATE. THE MIDDLE EAR'S THREE SMALL BONES TRANSMIT THE SIGNAL TO THE ELLIPTICAL WINDOW, THE GATEWAY TO THE INNER EAR. SOUND WAVES PASS THROUGH THE LIQUID-FILLED INNER EAR, INCLUDING THE SEMICIRCULAR CANALS AND COCHLEA, WHERE THEY ARE INTERPRETED BY THE BRAIN VIA THE AUDITORY NERVE. THE INNER EAR ALSO PLAYS A ROLE IN BALANCE THROUGH ITS FLUID. PROTECTION AGAINST DAMAGING SOUNDS, EXCEEDING 80 DB, INVOLVES MEASURES LIKE WEARING EARPLUGS, EAR MUFFS, LIMITING EXPOSURE TIME, AND INCREASING DISTANCE FROM THE SOURCE. • Pitch-determine by frequency, the high frequency the higher of the pitch • Volume-determined by amplitude, the higher altitude the louder sound • Tone-determined by how regular the sound waves are, the regular the soundwave the better the tone or quality of the sound. • Ultrasound: sound with frequencies that are higher than you audible to the human ear(higher than 20 khertz Electromagnetic radiation(light) Is caused by accelerating charges which have a changing magnetic field around them that induces a perpendicular changing electric field which then induces a changing magnetic field. Has energy associated with it therefore transfers energy. Doesn’t need a medium to travel and can travel through a vacuum. Speed of light in a vacuum(c)= EM spectrum The range of frequencies of EMF radiation 3 × 10
