31. A light wave travels with a wavelength of 4.0 x 10 m. What is the frequency? (A) Hz (C) Hz (B) Hz (D) Hz

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1 Physics 2204 Unit 4 Review ANSWERS (June 2013) 30. Which is an example f a lngitudinal wave? light wave sund wave radi wave water wave A light wave travels with a wavelength f 4.0 x 10 m. What is the frequency? Hz Hz Hz Hz 32. While at the beach, a student ntices that it takes 4.5 s fr eight cmplete waves t pass a pint. What is the frequency f the wave? 0.56 Hz 1.5 Hz 0.67 Hz 1. Hz 33. The critical angle fr the air-water bundary is 49. In which situatin will ttal internal reflectin ccur? Light travels frm air int water at an angle f incidence less than 49. Light travels frm air int water at an angle f incidence greater than 49. Light travels frm water int air at an angle f incidence less than 49. Light travels frm water int air at an angle f incidence greater than When water waves pass thrugh an pening, the waves tend t bend arund the crners. Which physics prperty des this illustrate? diffractin reflectin interference refractin 35. The index f refractin in salt is What is the speed f light in salt? 1.27 x 10 m/s 3.00 x 10 m/s 1.95 x 10 m/s 4.62 x 10 m/s 36. Mnchrmatic light f wavelength m illuminates tw slits that are separated by m. What is the angle t the secnd rder maximum? The sund intensity 2.5 m frm a sund surce is X. What is the sund intensity at a psitin 10.0 m frm the sund surce? 3. In which medium will the sund travel the fastest? air il irn water 39. High frequency sund waves are directed at an artery. Reflected waves have a different frequency than the incident waves due t the mvement f bld cells in an artery. Frm this difference the speed f bld cells can be determined. This is an applicatin f which wave prperty? Diffractin Interference Dppler Effect Refractin 40. A 0.0 m guitar string is vibrating at its fundamental frequency as shwn. What is the wavelength f the standing wave? 0.40 m 0.0 m 1.2 m 1.6 m

2 (June 2011) 30. A transverse wave is mving frm left t right. In which directin will a particle at the crest f the wave mve next? dwn right left up 31. On the wave belw, which pair f pints is in phase? A and E B and D C and D C and E 32. Which vertne is shwn in the clsed air clumn belw? 1st 2nd 3rd 4th 33. Given the index f refractin fr three materials, na = 1.00, ng = 1.50 and nw = 1.33, which best cmpares the speed f light in each material? va > vw > vg vg > vw > va va < vw < vg vw > vg > va 34. Which prperty f light explains why shadws frm? Dppler Effect Reflectin Rectilinear Prpagatin Refractin 35. A persn, standing in a canyn, shuts and hears an ech 1.63 s later. If the air temperature is 25.0 C, what is the distance t the canyn wall? 25 m 517 m 23 m 566 m 36. Tw students are at a cncert. Student A is standing 2 m frm the stage and student B is standing 6 m frm the stage. Hw des the sund intensity experienced by student A cmpare t that experienced by student B? 3 times greater 9 times greater 4 times greater 16 times greater 37. Eight waves strike a shreline in 4 s. What is the perid f the waves? 0.17 s 56 s 6.0 s 30 s 3. What is the critical angle fr light travelling frm ethyl alchl (n = 1.36) int air? What is the wavelength f the wave shwn?.00 m 16.0 m m m 40. An bject is traveling at Mach 2 n a day when the utside temperature is 15 C. Hw fast is the bject traveling? 171 m/s 664 m/s 341 m/s 62 m/s

3 (June 2010) 30. When a listener appraches a statinary sund surce, what happens t the perceived frequency? decreases subsnic increases unchanged 31. What is the expected angle f refractin as a beam f light travels frm glass ( ) at an angle f frm the nrmal, int water (? 32. A student is 3.0 m frm a mirrr. What distance frm the student des the virtual image appear t be? 1.5 m 6.0 m 3.0 m 9.0 m 33.What type f mechanical wave has particle mtin in the same directin as energy transfer? infrared transverse lngitudinal ultrasnic 34. A buy bbs up and dwn n the cean a ttal f 12 times in 6.0 secnds. What is the frequency f the mtin? 0.50 Hz 12 Hz 2.0 Hz 72 Hz 35. What is the speed f an airplane travelling at Mach 2 if the speed f sund is 332 m/s? 166 m/s 334 m/s 332 m/s 664 m/s 36. A radi statin sends ut electrmagnetic waves f length 3.11 m. At what frequency is the radi statin perating? 92.6 MHz 104 MHz 96.5 MHz 10 MHz 37. A blck f glass with an index f refractin f 1.42 is placed in frnt f a light surce. What is the speed f light in the blck? 3. A hiker is standing at ne end f a canyn that is 175 m wide n a day when the speed f sund is 341 m/s. Hw lng des it take the hiker t hear his ech? s 1.03 s s 1.95 s 39. When a guitar string f unknwn frequency is sunded with a 512 Hz tuning frk, 15 beats are heard in 5.0 s. Which is a pssible frequency f the guitar string? 497 Hz 515 Hz 512 Hz 527 Hz 40. A distant star is knwn t prduce a frequency f Hz. If it is mving away frm the Earth at m/s, what wavelength is bserved n Earth?

4 (June 2013) 44. (a) A persn is standing near a steep cliff and yells ut ludly. He hears his ech after s. The temperature utside is 22 C. Hw far away is the cliff? (4%) 44. (b) A 145 Hz tuning frk is held ver the pen end f an adjustable air clumn that is clsed at the ther end. The speed f sund in the air clumn is 345 m/s. (i) Sketch the first tw resnant patterns prduced inside the air clumn. (2%) (ii) Calculate the length f the air clumn which prduces the secnd resnant sund. (2%) 44. (c) Medium 2 in bth diagrams is the same substance. What is the critical angle,, fr light passing frm medium 2 int medium 3? (3%) (June 2011) 44. (a) A car is mving twards a statinary bserver at 15.1 m/s when the driver blws the hrn with a frequency f 70 Hz. If the speed f sund is 344 m/s, what is the frequency f the sund perceived by the bserver? (3%) 44. (b) When a tuning frk is held ver an adjustable tube pen at bth ends, the distance between the 1st and 2nd resnant lengths is measured t be 0.12 m. (i) Draw the standing wave pattern fr the 1st and 2nd resnant length (2%) (ii) What is the wavelength f the sund causing the resnance? (2%) (iii) What is the frequency f the tuning frk if the speed f sund is 344 m/s? (1%) 44. (c) Using the cncept f diffractin, explain why it is pssible t hear smene wh is standing just arund the crner f a building, but it is nt pssible t see them. (3%)

5 (June 2010) 44. (a) A bass guitar string is 1.3 m lng and is vibrating in the third harmnic. i) Sketch the standing wave pattern prduced. (1%) ii) Calculate the frequency if the speed f the wave is 11 m/s. (2%) 44. (b) A 310 Hz tuning frk is held ver the muth f an air clumn pen at ne end. If the speed f sund is 352 m/s, calculate the length f the air clumn which prduces the secnd resnant sund. (3%) 44. (c) An ambulance siren emits a frequency f 440 Hz. If the air temperature is, calculate the frequency heard by an bserver if the ambulance is cming tward him at 26 m/s. (4%) 44. (d) A light with a wavelength f m is shne thrugh tw slits which are m apart. Calculate the angle at which the first rder maxima ccur. (3%)

6 44. (e) A student is standing at the edge f a pl that is 2.3 m deep. A set f keys is at the bttm f the pl, 3.2 m frm the wall. The index f refractin fr air is 1.0 and fr water is 1.3. What is the angle f refractin in air? (3%) (June 2009) 44. (a) An air mattress flating n a lake bbs up and dwn 45 times in 5.0 minutes. Calculate the speed f the water waves prduced if the distance between their crests is 4.0 m. (3%) (b) A single slit f width m is illuminated by light f wavelength m. Calculate the angle at which the secnd rder minimum ccurs. (2%) 44. (c) A plice car has a speed trap set up n the highway. The radar gun emits a frequency f Hz and detects waves differing by Hz. Calculate whether the driver f this car will get a speeding ticket if the speed limit is km/h. (3%) 44. (d) The index f refractin fr diamnd is (i) If light travels frm air int diamnd, calculate the speed f light in diamnd. (2%) (ii) Calculate the critical angle fr diamnd in air. (2%) 44. (e) A standing wave pattern cntaining three antindes is prduced n a 6.0 m rpe. (i) Sketch the standing wave pattern prduced. (1%) (ii) Calculate the speed f the wave if the frequency f its surce is 5.5 Hz. (3%)