SMDEP Physics Waves Standing Waves Sound Waves Webpage

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SMDEP Physics Waves: Standing Waves, Sound Waves Webpage updated: http: //www. astro. yale. edu/krines/smdep

SMDEP Physics Waves: Standing Waves, Sound Waves Webpage updated: http: //www. astro. yale. edu/krines/smdep

Harmonic Motion and Waves in the Real World: • Harmonic Motion: springs (car shocks,

Harmonic Motion and Waves in the Real World: • Harmonic Motion: springs (car shocks, slinkys, DNA molecules) – Pendulums (clocks, swings, skyscrapers) – Periodic motion: orbiting satellites, planets, stars, galaxies • Waves: Sound – Sonar (bats, submarines) – Ultrasound (reflection/transmission of waves depends on density) • Waves: Light (Electromagnetic waves) – X-rays (see Ultrasound) – Lasers (pointers, grocery stores, cat toys, space weapons) – Radio (AM/FM, satellite), TV (broadcast) – Microwave (microwave ovens, cordless phones, cell phones) • Waves: Compressional (density waves) – Traffic slowdowns – Spiral galaxies – Sound

Ch 16, #3: distance 1. 2. 3. 4. 5. 6. 5 m 5000 m

Ch 16, #3: distance 1. 2. 3. 4. 5. 6. 5 m 5000 m Other Didn’t finish

Ch 16, #21 1. 2. 3. 4. 5. 6. 93 d. B 97 d.

Ch 16, #21 1. 2. 3. 4. 5. 6. 93 d. B 97 d. B 80 d. B 87 d. B Other Didn’t finish

Ch 16, #61: horn frequency? 1. 2. 3. 4. 5. 6. 132 Hz 126

Ch 16, #61: horn frequency? 1. 2. 3. 4. 5. 6. 132 Hz 126 Hz 120 Hz 66 Hz Other Didn’t finish

Ch 16, #63: beat frequency? 1. 2. 3. 4. 5. 6. 45 Hz 91

Ch 16, #63: beat frequency? 1. 2. 3. 4. 5. 6. 45 Hz 91 Hz 182 Hz 450 Hz Other Didn’t finish

What is required to produce a standing wave? 1. Two oppositely traveling waves 2.

What is required to produce a standing wave? 1. Two oppositely traveling waves 2. Same frequency 3. Same wavelength 4. Same amplitude 5. All of the above

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite directions. What is the amplitude of the standing wave they produce? 1. Same as either wave 2. Twice the amplitude of either wave 3. Half the amplitude of either wave 4. Zero 5. None of the above

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite directions. What is the wavelength of the standing wave they produce? 1. Same as original wavelength 2. Twice the original wavelength 3. Half the original wavelength 4. Cannot tell without knowing the phase

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite

Consider the sum of two similar waves (same amplitude, wavelength, frequency) traveling in opposite directions. What is the frequency of the standing wave they produce? 1. Same as original frequency 2. Different from the original frequency

Two sound waves combine to form beats, which occur 3 times a second. Two

Two sound waves combine to form beats, which occur 3 times a second. Two different sound waves combine to form a different set of beats, which occur 2 times a second. For which pair of waves is the frequency difference greater? 1. The first pair (3 beats a second) 2. The second pair (2 beats a second) 3. Same for both 4. Need more info

Doppler shift source moves away from detector àlonger (higher f) source moves toward detector

Doppler shift source moves away from detector àlonger (higher f) source moves toward detector àshorter (higher f)

Doppler shift detector moves away from source àlonger (higher f) detector moves toward source

Doppler shift detector moves away from source àlonger (higher f) detector moves toward source àshorter (higher f)

Doppler shift formula • • f’ = f (v v. D) _____ • (v

Doppler shift formula • • f’ = f (v v. D) _____ • (v v. S)

Two sound waves travel in the same region and thus interfere with each other.

Two sound waves travel in the same region and thus interfere with each other. What 10 is required to produce 100% destructive interference? 0 of 70 1. Waves have same frequency 2. Waves have same amplitude 3. Waves differ in phase by p radians 4. All of the above 5. None of the above

Joe hears a fire engine siren coming towards him at speed v. For Jane

Joe hears a fire engine siren coming towards him at speed v. For Jane to hear the identical pitch (frequency) from the 10 siren of a stationary fire engine, she would have to: 1. 2. 3. 0 of 70 4. 5. Be standing still Be moving towards the fire engine at speed v Be moving towards the fire engine at some other speed Be moving away from the fire engine at speed v Need more info

A submerged submarine sends a sonar wave into the surrounding ocean, and it (the

A submerged submarine sends a sonar wave into the surrounding ocean, and it (the wave) reflects off a distant object. 10 If the sub is moving away from the object that reflects the sonar wave, the frequency of the reflected wave is 1. 2. 3. 4. 0 of 70 5. Smaller than Equal to Larger than (depends on motion of distant object) (need more info) … the frequency of the emitted wave