Chapter 12: Sound Describe production of sounds Measure the speed of sound Relate pitch and loudness to frequency and amplitude Describe how sound travels Sound is a longitudinal (compression) wave Sound is created by vibrating the molecules of a medium Measuring the speed of sound Frequency and pitch are related Amplitude and loudness are related Human hearing range Sound waves must have a medium to travel through. The denser the medium, the faster the sound wave travels. Sound waves are composed of compression (crest) and rarefaction (trough) String Instruments: stings cause body of instrument to vibrate and create sound waves Wind instruments tube vibrates a column of air Percussion instruments body of instrument vibrates. The sound source and sound detector are separated by a known distance. The time interval is measured electronically. Speed is calculated s = d/t f = 1/T (inverse of period) units are Hertz (Hz) = cycles per second high frequency sounds are perceived as high pitch The greater the amplitude of a sound wave, the greater the energy. Sound intensity is a measure of energy. Loudness is perceived volume. High amplitude, louder perceived sound 20 Hz to 20,000 Hz
Chapter 13: Light Describe how a plane mirror forms and image Construct ray diagrams of reflection using law of reflection. Describe refraction of light Calculate refractive index using Snell s Law Describe total internal reflection Use ray diagrams to explain how a lens forms images Explain how a magnifying glass works Law of reflection: The angle of incidence (i) equals the angle of reflection. Mirrors form virtual images that appear equal distance behind the mirror and are reversed Light is refracted (bent) when it moves from one medium to another. The index of refraction (n) of the medium determines the angle of refraction Refractive index n n = speed of light/speed of light in medium Snell s Law n = sin(i)/sin(r)
Ray diagram for refraction Ray diagram of real image. Image is real (can project on a screen) Image is on opposite side of lens from the object Image is inverted Image may be reduced or enlarged Ray diagram of virtual image (magnifying glass) Image is virtual (can t be projected on screen) Image is upright and enlarged Total internal reflection The angle of incidence is greater than the critical angle of the medium
Chapter 14: Properties of Waves Describe transverse and longitudinal waves Explain speed, amplitude, frequency and wavelength Apply the wave equation Describe reflection, refraction, and diffraction of waves Identify parts of a wave Frequency and period are related Period (T) = time for one cycle Frequency (f) = cycles per second T = 1/f f = 1/T The wave equation relates speed, wavelength and frequency v = λf v = speed m/s λ = wavelength m f = frequency Hz Reflection of waves Frequency, wavelength and speed do not change Refraction of waves Frequency remains the same, speed and wavelength change.
Diffraction wave spreads out
Chapter 15: Spectra Describe dispersion of light by a prism Describe features of electromagnetic spectrum Understand all EM waves travel at speed of light Apply the wave equation to EM waves A prism will disperse white light. White light will be dispersed into different wavelengths by refraction. Longer wavelengths (red) will be bent less than shorter wavelengths (violet) The electromagnetic spectrum relates wavelength, frequency, and energy EM waves travel at the speed of light and behave according to the wave equation Long λ, low f, low energy (radio waves) Short λ, high f, high energy (gamma rays) Visible light is in the middle of the EM spectrum Speed of light c = 3 x 10 8 m/s EM Wave equation c = λf