Cover Sheet-Block 6 Wave Properties

Transcription

1 Cover Sheet-Block 6 Wave Properties Name Standards-Physics 4 a b c d 4a. Students know waves carry energy from one place to another. 4. b. Students know how to identify transverse and longitudinal waves in mechanical media, such as springs and ropes, and on the earth (seismic waves). 4. c. Students know how to solve problems involving wavelength, frequency, and wave speed. 4. d. Students know sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates. Objective Waves What are waves? Waves carry energy / information from one place to another using oscillation Wave Properties- Identify theses oscillations using terms like wavelength, amplitude, frequency, propagation direction and speed. Identify transverse and longitudinal waves in mechanical media, such as springs and ropes, and on the earth (seismic waves). Wave Behavior- Understand wave motion in a material and in a vacuum. Describe constructive and destructive interference of more than 1 wave and /or a material. Sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates. 1. Coversheet 2. WCW 3. Vocab- pg (19 words) 4. HW pg Physics to go # Notes-Wave Properties 6. Problems on wave properties (back of 5 okay) 7. Notes Sound 8. Handout Wave Equation 9. Wave Quiz HO 10. Copy Shaded box s on pg

2 Warm-up: 1 Sketch and Describe Page #2 WCW Name Breaking the speed of sound Longitudinal Wave Parallel Surfing Wave Transverse Wav Perpendicular Wrap-up 1 Explain the relationship between Wavelength, speed and frequency. (the eq. you wrote down) Warm-up 2 Sketch and Answer How is a roller coaster an example of wave motion? Vibrations and or Oscillations occur Critical thinking 2 Explain the phrase, Two waves constructively interfere. Wrap-up 2 Draw Longitudinal or Compression Wave

3 Warm-up 3 How does a flute make different sounds or wavelengths? As you cover the different holes you create different lengths Of waves. Diff wavelength different frequencies, different Sounds Critical thinking 3 Describe the relationship between Frequency and Wavelength. Wrap-up 3 Only Answer, Just write Agree or disagree 1 Sound waves transfer energy only in matter. 2 The loudness of a sound wave increases as the frequency of a wave increases. 3 Sound travels faster in warm air than in cold air. 4 Sound usually travels faster in gases than in solids. 5 The pitch of a sound you hear depends on whether the source of the sound is moving relative to you. 6 Sound waves do not spread out when they pass through an opening. 7 A vibrating string whose length is fixed can produce sound waves of more than one frequency. 8 The body of a guitar helps make the sound of the vibrating strings louder. 9 Changing the length of a vibrating air column changes the pitch of the sound produced.

4 Name Page #3 Vocabulary 19 total Pg words 1) Transverse pulse or wave: motion of medium perpendicular to motion 2) Amplitude: the height of a wave crest, it s the energy amount 3) ic wave: a repetitive pulses, ocean wave s 4) Standing wave: wave moves between two points, jump-rope 5) Crest: the highest point of a wave 6) Wavelength: the distance between consecutive points of a wave Crest to crest 7) Frequency: the number of waves produced per unit of time, reciprocal of the 8) Compression pulse or wave: longitudinal, caused by compression and expansion. Sound 9) Longitudinal pulse or wave: the motion of the medium is parallel to the wave motion. Traffic 10) Trough: the lowest point of a wave 11) Node: a spot on a standing wave where the medium is motionless Pg word 12) Pitch: the quality of a sound dependent primarily on the frequency of the sound waves produced by the source Some other Vocabulary from Standards 13) Vacuum no air 14) Light waves electromagnetic spectrum 15) Sound waves Need medium (material) to travel 16) Wave propagating movement of wave through material 17) Expansion (rarefaction) spreading of material during wave 18) Acoustic waves sound wave from vibration in a hole 19) Wave speed equal to frequency times wavelength

5 Page 4 Hw pg Physics to go # 2-6 Name

6 Page 5 Notes-Wave Properties Each Line Answers a Test Question Name 1) A wave is a repeating disturbance that transfers energy through matter or open space. 2) Waves that use matter to transfer energy are called mechanical waves. 3) Light waves travel in both a vacuum and a medium 4) The matter through which a mechanical wave travels is called a medium 5) In transverse waves, matter in the medium moves back and forth at right angles to the direction the wave travels. 6) In Longitudinal or compressional waves, matter in the medium moves forward and backward in the same direction the wave travels. 7) Sound waves are compressional waves. 8) Sound waves cannot travel in outer space because they are mechanical waves they travel through a medium 9) What is the region of a compressional wave where particles are far apart called? rarefaction 10) What type of wave does not require matter to carry energy? Transverse 11) Amplitude is a measure of the energy in a wave. 12) A transverse wave has amplitude 13) The Wavelength is the distance from the top of one crest of a transverse wave to the top of the next crest in that wave. 14) The frequency of a wave is how many wavelengths pass a fixed point each second

7 Page 6 Problems Wave Properties Name 1. Which wave above is a transverse wavelongitudinal wave- 2. Draw Transverse wave, label crest and trough Longitudinal wave, label compression and rarefaction 3. What is this wave s frequency? ( just divide cycles/second) 6 cycles in 1 seconds 4. What is the period of the wave in #3? (Flip three s answer) 5. What is this wave s Frequency? ( just divide cycles/second) 6 cycles in 2 seconds, 6. What is the period of a wave in #5?

8 Name Page 7 Notes Sound 1. Sounds are produced by vibrations 2. What type of waves are sound waves? compressional 3. The two types of regions that make up compressional waves are compressions and rarefactions 4. Sound travels faster in air than in water or oil because of the mediums index of refraction or density 5. How does temperature of a medium affect the speed of sound waves? As the temperature of a substance increases, sound waves in it move faster 6. The human perception of sound intensity is loudness 7. The intensity of sound is measured in units called decibels 8. Sound waves with frequency of 10,000 Hz is a high pitch sound 9. Music follows a specified pattern of sounds 10. The pitch is the frequency at which a material tends to vibrate when it is disturbed. 11. Resonance is the ability of a medium to vibrate by absorbing energy at its natural frequency. 12. A(n) natural frequency is a vibration whose frequency is a multiple of the fundamental frequency. 13. The echoing effect produced by many reflections of sound is called reverberation 14. In the human ear, sound waves are gathered in the outer ear 15. Musical Instruments Groups: String, Wind, Percussion 16. How does a musician change the note played on a woodwind instrument? by changing the length of resonating column of air 17. In the human ear, the membrane that stretches across the ear canal like a drumhead is called the eardrum 18. The human ear can detect frequencies ranging from about 20 Hz to about 20,000 Hz. 19. Time equals distance divided by speed: t = d s = 75 m 343 m/s = 0.22 s. 20. Distance equals the product of time and speed: d = t s = s 5,940 m/s = 65 m. 21. The total distance is 74 m. Time equals distance divided by speed: t = d s = 74 m 1,483 m/s = s. 22. When two notes close in frequency are played together, the sound waves interfere to form a beat, a new sound whose loudness increases and decreases several times a second.

9 Item # 8 Wave Speed, Frequency, & Wavelength Practice Problems v = f λ c = 300,000,000m/s c = fλ (c = 3x10 8 m/s) Use the above formulas and information to help you solve the following problems. Show all work, and use the factor-label method to perform all necessary conversions. 1. Sound waves in air travel at approximately 330m/s. Calculate the frequency of a 2.5m-long sound wave. f = 132Hz 2. A wave on a certain guitar string travels at a speed of 200m/s. Calculate the wavelength of an A note sounding at 440Hz. λ= 0.45m 3. A low-frequency radio wave has a frequency of 250,000Hz. What is the wavelength of this radio wave? (Hint: Don t forget that this is an electromagnetic wave, and therefore you should automatically know its speed.) λ = 1200m 4. A certain microwave has a wavelength of meters. Calculate the frequency of this microwave. f = 9.375x10 9 Hz 5. A certain radio wave has a wavelength of 7 inches. a. Convert the wavelength of this radio wave into meters. (1 meter = inches) 0.178m b. Find the frequency of this radio wave. f = 1.69x10 9 Hz 6. A certain wave on the border between microwaves and infrared waves has a frequency of 2x10 12 Hz. a. Calculate the wavelength of this wave in meters. λ = 1.5x10-4 m b. Convert the wavelength from part A into millimeters. (1 meter = 1000 millimeters) 0.15mm 7. The wavelengths of visible light range from approximately 400 nanometers to 750 nanometers. a. Convert the 750nm wavelength of the red light into meters. ( 1 nanometer = 1x10-9 meters) 750x10-9 m (or 7.5x10-7 m) b. Convert the 400nm wavelength of the violet light into meters. 400x10-9 m (or 4.0x10-7 m) c. Now find the frequency of the higher-frequency colored light of parts A and B. (Hint: Before calculating, give some thought to the relationship between frequency and wavelength. Then you only need to calculate for the one color that corresponds to the higher frequency.) f = 7.5x10 14 Hz

10 VOCABULARY Review The following terms are from Waves: Energy in Motion. Fill in the number of each term next to its closest definition. 1. acoustics 2. amplitude 3. crest 4. decibel 5. diffraction 6. frequency 7. Hertz 8. interference 9. light 10. reflection 11. refraction 12. reverberation 13. spectrum 14. trough 15. wave A. to cast back light, heat, sound, etc. from a surface B. number of vibrations of cycles per unit of time C. mutual action of two waves of the same frequency reinforcing or neutralizing each other D. low point of a wave E. study of how sounds are created, transmitted and received F. electromagnetic waves that can travel through the vacuum of space G. high point of a wave H. bending of a ray or wave of light, heat or sound as it passes from one medium to another medium of different density I. unit for measuring the volume of sound J. multiple reflection of sound waves K. transforming of a straight wave front into a curved wave front L. series of colored bands diffracted and arranged in order of wavelengths M. a disturbance that carries energy but not matter from one place to another N. difference in height between the crest and the trough of a wave O. international unit of measurement for a frequency, equal to one cycle per second Waves & Electromagnetic Spectrum Worksheet Directions: Use the word bank to answer the following questions. Each word will be used only once. Crest Frequency Mechanical Infrared Trough Transverse Radio Gamma Wavelength Longitudinal Ultraviolet X-Rays Visible Light Amplitude Electromagnetic 1. waves are used to penetrate solids and are used in doctor s offices and as airports. 2. is the distance between one point of a wave to the same point in the next wave. 3. is the number of waves per unit of time. 4. waves occur when the motion of the medium is parallel to the direction of the wave. 5. waves have a color spectrum known as ROYGBIV. 6. waves disturb matter. 7. The is the top of a wave. 8. The is the bottom of a wave. 9. is the maximum distance that matter is displaced from the resting position. 10. waves are produced by stars and galaxies. 11. waves occur when the motion of the medium is at right angles (perpendicular) to the direction of the wave. 12. waves are often used in heat lamps. 13. waves are utilized by insects to locate nectar. 14. waves are transverse waves that disturb electromagnetic fields. 15. waves have the shortest wavelength and the highest frequency.

11 Item # 9 Wave Properties Quiz Name per Ics1 Semester 1 Block 6 Wave Properties Quiz Waves may energy through a vacuum or through matter. Light waves, transport energy in ways. Sound waves and most other waves occur only in. Even waves through matter transport energy without any net movement of the matter, thus differing from other means of energy transport, such as, a waterfall, or even a thrown object. Fill in blank: Propagating, Convection, Transport, Matter, Both Waves that propagate with mechanics are either longitudinal or transverse waves. The disturbance in longitudinal waves is to the direction of propagation and causes compression and expansion (rarefaction) in the medium carrying the wave. The disturbance in transverse waves is to the direction of propagation of the wave. Examples of waves are sound and earthquake waves. In transverse waves a conducting medium, or a test particle inserted in the wave, moves perpendicular to the direction in which the wave propagates. Examples of are earthquake waves and electromagnetic (or light) waves. Fill in blank: Perpendicular, Waves, p-type, Parallel, Longitudinal, Transverse waves, s-type Sound waves, sometimes called, are typically produced when a vibrating object is in contact with an elastic medium, which may be a solid, a liquid, or a gas. A sound wave is longitudinal, consisting of regions of high and low pressure (and therefore of and ) that propagate away from the source. Fill in blank: Acoustic waves, Compression, Rarefaction

12 Item 10 Copy shaded box from pg 330 and 331