Quiz 5 PRACTICE--Ch12.1, 13.1, 14.1

Transcription

1 Nae: Class: Date: ID: A Quiz 5 PRACTICE--Ch2., 3., 4. Multiple Choice Identify the choice that best copletes the stateent or answers the question.. A bea of light in air is incident at an angle of 35 to the surface of a rectangular block of clear plastic (n.49). What is the angle of refraction? a. 2 b. 42 c. 23 d Sound waves a. are longitudinal waves. b. are transverse waves. c. do not require a ediu for transission. d. are a part of the electroagnetic spectru. 3. When a light ray oves fro air into glass, which has a higher index of refraction, its path is a. bent toward the noral. b. bent away fro the noral. c. parallel to the noral. d. not bent. 4. Which portion of the electroagnetic spectru is used in a icroscope? a. gaa rays b. infrared waves c. ultraviolet light d. visible light 5. A wave travels through a ediu. As the wave passes, the particles of the ediu vibrate in a direction perpendicular to the direction of the wave s otion. The wave is a. a pulse. b. electroagnetic. c. transverse. d. longitudinal. 6. At a large distance fro a sound source, spherical wave fronts are viewed as a. plane waves. b. wavelengths. c. rays. d. troughs. 7. In the diagra above, use the superposition principle to find the resultant wave of waves Q and R. a. b b. a c. d d. c 8. Carbon tetrachloride (n.46) is poured into a container ade of crown glass (n.52). If a light ray in the glass is incident on the glass-to-liquid boundary and akes an angle of 30.0 with the noral, what is the angle of the corresponding refracted ray with respect to the noral? a b c d If you are reading a book and you ove twice as far away fro the light source, how does the brightness at the new distance copare with that at the old distance? It is a. one-half as bright. b. one-fourth as bright. c. twice as bright. d. one-eighth as bright. 0. In general, sound travels faster through a. gases than through liquids. b. solids than through gases. c. gases than through solids. d. epty space than through atter.

2 Nae: ID: A. The distance between wave fronts of plane waves corresponds to of a sound wave. a. two rarefactions b. one copression c. one wavelength d. two aplitudes 2. The trough of the sine curve used to represent a sound wave corresponds to a. the wavelength. b. a copression. c. a rarefaction. d. the aplitude. 3. Refraction is the bending of a wave disturbance as it passes at an angle fro one into another. a. ediu b. area c. glass d. boundary 4. Consider two identical wave pulses on a rope having a fixed end. Suppose the first pulse reaches the end of the rope, is reflected back, and then eets the second pulse. When the two pulses overlap exactly, what will be the aplitude of the resultant pulse? a. sae as the original pulses b. half the aplitude of the original pulses c. zero d. double the aplitude of the original pulses 5. Pitch depends on the of a sound wave. a. speed b. power c. frequency d. aplitude 6. Atospheric refraction of light rays is responsible for which of the following effects? a. spherical aberration b. total internal reflection in a gestone c. irages d. chroatic aberration 7. What is the wavelength of an infrared wave with a frequency of Hz? a b c d Part of a pencil that is placed in a glass of water appears bent in relation to the part of the pencil that extends out of the water. What is this phenoenon called? a. diffraction b. reflection c. refraction d. interference 9. A train oves down the track toward an observer. The sound fro the train, as heard by the observer, is the sound heard by a passenger on the train. a. lower in pitch than b. the sae as c. higher in pitch than d. a different tibre than 20. When a echanical wave s aplitude is reduced by half, the energy the wave carries in a given tie interval is a. decreased to one-fourth. b. doubled. c. decreased to one-half. d. increased by a factor of Two echanical waves that have positive displaceents fro the equilibriu position eet and coincide. What kind of interference occurs? a. coplete destructive b. destructive c. none d. constructive 22. What is the frequency of an electroagnetic wave with a wavelength of.0 0 5? a Hz b Hz c Hz d Hz 23. What is the frequency of infrared light of wavelength? a Hz b Hz c Hz d Hz 24. The Doppler effect occurs with a. only transverse waves. b. only water waves. c. all waves. d. only sound waves. 25. Which is an exaple of refraction? a. Light is bent slightly around corners. b. In a irror, when you lift your right ar, the left ar of your iage is raised. c. A parabolic irror in a headlight focuses light into a bea. d. A fish appears closer to the surface of the water than it really is when observed fro a riverbank. 26. A ray of light in air is incident on an air-to-glass boundary at an angle of exactly 30.0 with the noral. If the index of refraction of the glass is.65, what is the angle of the refracted ray within the glass with respect to the noral? a b. 8.0 c d If you know the wavelength of any for of electroagnetic radiation, you can deterine its frequency because a. the speed of light increases as wavelength increases. b. the speed of light varies for each for. c. all wavelengths travel at the sae speed. d. wavelength and frequency are equal. 2

3 Nae: ID: A 28. In the diagra above, use the superposition principle to find the resultant wave of waves W and Z. a. c b. b c. d d. a 29. Two echanical waves can occupy the sae space at the sae tie because waves a. are atter. b. cannot pass through one another. c. are displaceents of atter. d. do not cause interference patterns. 30. The relationship between frequency, wavelength, and speed holds for light waves because a. all fors of electroagnetic radiation travel at a single speed in a vacuu. b. light travels slower in a vacuu than in air. c. different fors of electroagnetic radiation travel at different speeds. d. light travels in straight lines. 3. Which of the following wavelengths would produce standing waves on a string approxiately 3.5 long? a b c d When two echanical waves coincide, the aplitude of the resultant wave is always the aplitudes of each wave alone. a. the su of b. the sae as c. less than d. greater than 33. Which is not correct when describing the foration of rainbows? a. Sunlight is internally reflected on the back side of a raindrop. b. All wavelengths refract at the sae angle. c. Sunlight is spread into a spectru when it enters a spherical raindrop. d. A rainbow is really spherical in nature. 34. The of light can change when light is refracted because the ediu changes. a. transparency b. ediu c. wavelength d. frequency 35. The highness or lowness of a sound is perceived as a. ultrasound. b. wavelength. c. copression. d. pitch. 36. When a light ray passes fro water (n.333) into diaond (n 2.49) at an angle of 45, its path is a. parallel to the noral. b. bent toward the noral. c. bent away fro the noral. d. not bent. 37. What is the wavelength of icrowaves of Hz frequency? a b c. 0.0 d Which of the following is not an exaple of approxiate siple haronic otion? a. a car s radio antenna waving back and forth b. a piano wire that has been struck c. a child swinging on a swing d. a ball bouncing on the floor 39. When red light is copared with violet light, a. both have the sae wavelength. b. both travel at the sae speed. c. both have the sae frequency. d. red light travels faster than violet light. 3

4 Nae: ID: A 40. The of light can change when light is refracted because the velocity changes. a. ediu b. transparency c. frequency d. wavelength Proble 4. The objective lens of a copound icroscope has a focal length of.00 c. A specien is.25 c fro the objective lens. The iage fored by the objective lens is 0.80 c inside the focal point of the eyepiece whose focal length is.50 c. What is the distance fro the eyepiece to the iage fored by the eyepiece lens? 42. Yellow-green light has a wavelength of 560 n. What is its frequency? 43. A student wishes to construct a ass-spring syste that will oscillate with the sae frequency as a swinging pendulu with a period of 3.45 s. The student has a spring with a spring constant of 72.0 N/. What ass should the student use to construct the ass-spring syste? 44. A certain radio wave has a frequency of Hz. What is its wavelength? 45. The frequency of an X ray is Hz. What is the X ray s wavelength? 46. A fiber-optic cable (n.53) is suberged in water (n.33). Predict whether light will be refracted or whether it will undergo total internal reflection if the angle of incidence is between 65 and An object is placed along the principal axis of a thin converging lens that has a focal length of 28 c. If the distance fro the iage in front of the lens is 24 c, what is the distance fro the object to the lens? 48. A 0.20 kg ass suspended fro a spring oves with siple haronic otion. At the instant the ass is displaced fro equilibriu by 0.050, what is its acceleration? (The spring constant is 0.0 N/.) 49. A ass on a spring vibrates in siple haronic otion at an aplitude of 8.0 c. If the ass of the object is 0.20 kg and the spring constant is 30 N/, what is the frequency? 50. A portion of infrared light in the electroagnetic spectru has a wavelength of 725 µ. What is the frequency of this portion of infrared light? 4

5 Quiz 5 PRACTICE--Ch2., 3., 4. Answer Section MULTIPLE CHOICE. ANS: C θ i 35 n i.00 n r.49 Rearrange Snell s law, n i sinθ i n r sinθ r, and solve for θ r. θ r sin n i sinθ n i r ˆ sin ( sin 35 ) 23 PTS: DIF: IIIA OBJ: ANS: A PTS: DIF: I OBJ: ANS: A PTS: DIF: II OBJ: ANS: D PTS: DIF: I OBJ: ANS: C PTS: DIF: I OBJ: ANS: A PTS: DIF: I OBJ: ANS: A PTS: DIF: II OBJ: ANS: D θ i 30.0 n i.52 n r.46 Rearrange Snell s law, n i sinθ i n r sinθ r, and solve for θ r. θ r sin n i sinθ n i r ˆ sin ( sin 30.0 ) 3.4 PTS: DIF: IIIB OBJ: ANS: B PTS: DIF: II OBJ: ANS: B PTS: DIF: I OBJ: ANS: C PTS: DIF: II OBJ: ANS: C PTS: DIF: I OBJ: ANS: A PTS: DIF: I OBJ: ANS: C PTS: DIF: IIIA OBJ: ANS: C PTS: DIF: I OBJ: ANS: C PTS: DIF: I OBJ: 4-3.2

6 7. ANS: D f Hz s c /s Rearrange the wave speed equation, c fλ, to isolate λ, and calculate. λ c ˆ /s f s ˆ PTS: DIF: IIIA OBJ: ANS: C PTS: DIF: I OBJ: ANS: C PTS: DIF: I OBJ: ANS: A PTS: DIF: II OBJ: ANS: D PTS: DIF: I OBJ: ANS: C λ c /s Rearrange the wave speed equation, c fλ, to isolate f, and calculate. f c ˆ /s λ ˆ s Hz PTS: DIF: IIIA OBJ: ANS: B λ c /s Rearrange the wave speed equation, c fλ, to isolate f, and calculate. f c ˆ /s λ ˆ s Hz PTS: DIF: IIIA OBJ: ANS: C PTS: DIF: I OBJ: ANS: D PTS: DIF: II OBJ: 4-. 2

7 26. ANS: B θ i 30.0 n i.00 n r.65 Rearrange Snell s law, n i sinθ i n r sinθ r, and solve for θ r. θ r sin n i sinθ n i r ˆ sin sin 3.0 ˆ PTS: DIF: IIIA OBJ: ANS: C PTS: DIF: I OBJ: ANS: B PTS: DIF: II OBJ: ANS: C PTS: DIF: I OBJ: ANS: A PTS: DIF: II OBJ: ANS: B PTS: DIF: IIIC OBJ: ANS: A PTS: DIF: I OBJ: ANS: B PTS: DIF: I OBJ: ANS: C PTS: DIF: I OBJ: ANS: D PTS: DIF: I OBJ: ANS: B PTS: DIF: II OBJ: ANS: C f Hz s c /s Rearrange the wave speed equation, c fλ, to isolate λ, and calculate. λ c ˆ /s f s ˆ 0.0 PTS: DIF: IIIA OBJ: ANS: D PTS: DIF: I OBJ: ANS: B PTS: DIF: II OBJ: ANS: D PTS: DIF: II OBJ: 4-. 3

8 PROBLEM 4. ANS: c F o.00 c p o.25 c F e.50 c p e.50 c 0.80 c.32 c The focal length and object distance of the objective lens do not enter into the calculation. The iage of the objective lens is the object of the eyepiece lens. Rearrange the thin-lens equation, q e f e p e p + q f, and solve for q..50 c.32 c c c 0.09 c q e c (since q is negative, the iage is virtualand in front of the lens) PTS: DIF: IIIC OBJ: ANS: Hz λ 560 n c /s Rearrange the wave speed equation, c fλ, to isolate f, and calculate. f c ˆ /s λ ˆ s Hz PTS: DIF: IIIA OBJ:

9 43. ANS: 2.7 kg T pendulu 3.45 s k 72.0 N/ If both systes have the sae frequency, they will also have the sae period. Therefore, the given period ay be substituted into the equation for a ass-spring syste. T 2π k T 2 4π 2 k ˆ T2 k 4π 2 ( 3.45 s) 2 ( 72.0 N/) 4π kg PTS: DIF: IIIC OBJ: ANS: or 50 f Hz s c /s Rearrange the wave speed equation, c fλ, to isolate λ, and calculate. λ c ˆ /s f s ˆ or 50 PTS: DIF: IIIA OBJ: ANS: f Hz s c /s Rearrange the wave speed equation, c fλ, to isolate λ, and calculate. λ c ˆ /s f s ˆ PTS: DIF: IIIA OBJ:

10 46. ANS: Since the angle of incidence is greater than the critical angle, 60.4, the light ray will undergo total internal refraction. n optic cable.53 n water.33 θ i Rearrange the criticalangle equation, sin θ c n r n i, to find θ c. θ c sin n ˆ r n i n ˆ water sin n optic cable.33 ˆ sin Since the angle of incidence is greater than the critical angle, the light ray will undergo total internal refraction. PTS: DIF: IIIB OBJ: ANS: 3 c q 24 c (q is negative, since the iage is in front of the lens) f 28 c (f is positive, since this is a converging lens) Rearrange the thin-lens equation, p f p 3 c p + q f, and solve for p. q 28 c 24 c c c c PTS: DIF: IIIB OBJ: ANS: 2.5 /s kg k 0.0 N/ x F kx and F a a kx a kx (0.0 N/)( ) 0.20 kg a 2.5 N/kg 2.5 /s 2 PTS: DIF: IIIA OBJ: -.3 6

11 49. ANS: 4.0 Hz x 8.0 c (This value is not relevant to the proble.) 0.20 kg k 30 N/ T 2π k and f T, so f 2π k 2π k 2π 30 N/ 0.20 kg 4. Hz PTS: DIF: IIIB OBJ: ANS: Hz λ 725 µ c /s Rearrange the wave speed equation, c fλ, to isolate f, and calculate. f c ˆ /s λ ˆ s Hz PTS: DIF: IIIA OBJ: