Simple Harmonic Motion - Physics - Solved Paper, Exams of Physics

Download Simple Harmonic Motion - Physics - Solved Paper and more Exams Physics in PDF only on Docsity! Ow Physics 124 - Analytical Physics SECOND COMMON HOUR EXAM Monday, Apr. 4, 2011 > al SIGN HERE NOW: The exam will last from 9:40 - 11:00 p.m. Use a #2 pencil to make entries on the answer sheet. Enter ID information items 2-5, now, on the answer sheet before the exam starts... In the section labeled NAME (Last, First, M.I.) enter your lasi name, then fill in the empty circle for a blank, then enter your first name, another blank, and finally your middle initial. Under STUDENT # enter your 9-digit RUID Number. Enter 124 under COURSE; you may ignore the section number. Under CODE enter the exam code given above. During the exam, you may use pencils, a calculator, and one 8.5 x 11 inch sheet (both sides) with formulas and notes. There are 18 multiple-choice questions on the exam. For each question, mark only one answer on the answer sheet. There is no deduction of points for an incorrect answer, so even if you cannot work out the answer to a question, you should make an educated guess. At the end of the exam, hand in the answer sheet and this SIGNED cover page. Retain the exam questions attached for future reference and study. When you are asked to open the exam, make sure that your copy contains all 18 questions. Raise your hand if this is not the case, and a proctor will help you. Also raise your hand during the exam if you have a question. Please have your student ID ready to show to the proctor during the exam. Possibly useful information: at the earth’s surface g = 9.8 m/' 8", Usoundin air re 340 m/s, Pair *¥ 1.2 kg/m®, the parallel axis theorem is J = Inpoutem tml? and Ip = 1xi0- W/m? in the dB equation. GRADE 50%, 7%, 662, \O% And havelest e A 5 ke block attached to a massless spring (constant 20 N/m) undergoes w= an = fe simple harmonic motion with amplitude 0.2 m. At time t = 0 its position = is x = 0.0 m and it is moving in the +a direction. Which of the following equations gives x(t) for the block? YY “1 a 2B, 20${Ue) a) «= 0.2 cos(2t) m ) «= 0.2 cos(t/2) m c) x = 0.2 cos(2#+ 0.5) m d) 2 = 0:2 coslt/2 + n/2) m a 16) =0,2¢05(ue-17/2) An object attached to a massless spring undergoes simple harmonic motion of amplitude A along the z axis. At which of the following positions is the kinetic energy of the object twice as large as its potential energy? Kruse burrs Qh \cAY) by 2 = A/y2 Aarne & y2= A223 c) 2=A/2 WA E/3 d) c= A/3 ye ANS e) The kinetic energy is never two times the potential energy. An object undergoes simple harmonic motion of amplitude A along the x axis. At which of the following positions can the acceleration be greater than 0 but the velocity be less than 0? a) s=—-A usr O,ar>o by) @=—A/2 6 cantor. +e) aro £= v conbe H-), C=O d) t=A/2 oF Can be -) AGO 8) @=A verOQ, 460 What is the angular frequency w of simple harmonic motion of a physical pendulum consisting of a solid disk of mass m and radius r undergoing small oscillations about a point on its edge? It might help to remember that the moment of inertia of this disk about its center of mass is J = mr?/2. a) V9 [r axis of rotation s , outofpaper /: ) movement of di 1 OFS 3) in plane of papel coilel § Ks ) Vv 4g/r a ce DZ om, problem on W phys = se wiak Es w+ Se? CxaW Rext ced (Bib duath woud Be lecture Fnotes qageI@ W ohys = { at sey -(B 13. What is the angle of the shock wave made by a plane traveling at 3.0 times the speed of sound? a) 70.5° = 1.23 radians GRave (BI. = 0.340 radians shock uli - C. ) 18.4° = 0.322 radians ~ ° d) 0.006° = 0.058 radians oe Velocity direction BA% e) There is no shock wave at that ‘ we 2 . speed. “7 duck COS . s \ Problem ain 8 drocle > sev 0d (Bolan = la, om Emmet Soho = 14.5? 14. A 1.0 m long string with mass density 1.0107? kg/m is under a tension of 200 N. Both ends of the string are fixed in place. What is the fundamental resonance frequency of the string? a) 340 Hz b) Not enough information is given to determine the fundamental res- onance frequenc; ‘4 y N Gad 7 ak c) 170 Hz \ f 12% d) 140 He Gods yuu? Wg 2 ae = Woofie® = 70 He 15. What length does a long tube with one open penuacone one closed end have to be so that its armonic is the same frequency as the n=1 fundamental harmonic of a 080 m ret with both ends open? “Cc gy ~ ne wed Sov ud Govmeritc b) 0.30 m 5SB% c) 040m AY nei Srna wer bef d) 0.23 m wea) \ e) 0.80m 3 da Db < 6b = 203 my) =D. 45in 4. = ait 4 16. What is the beat frequency between a 500 Hz source and a 502 Hz source? a) It depends on the speed of sound. b) 0.5 Hz 85% ¢c Hz Q 2H Gece = £-4, = 50 .~Seo= 2 17. An ant desparately clings to a string along which a sinusoidal wave is trav- eling, so that the ant oscillates back and forth. The wave has an amplitude of 0.02 m, a wavelength of 0.4 m, and a speed of 10 m/s. What is the maximum speed at which the ant moves? CRA DE. a) It cannot be determined from the information given. Waw / ia —_ b) 10 m/s 2 = 83% ¢ m/s Ome? wa > weok ) / spk e) 0.5 m/s = Vw 0.02) = hu QCA) (0.03 Ee 18. Two out-of-phase speakers are positioned 3.5 m apart, both pointing toward a wall 5.0 m in front of them. A listener positioned at the wall, midway between the speakers, hears virtually nothing (destructive interference). Only after moving to one side by 0.84 m does the listener begin to hear a loud sound (constructive interference). What is the frequency of the sound emitted by the speakers? Pestcuctive Constructive / interference ‘interference Sse AG ‘To b) 620 Ha c) 64 Hz i -of-phas d) 400 Ha Sunken e) 200 Hz pdada dy Aare?! -AGrs-eh +57 = 5.b3m- 508m 2 7™ b2=Om > ovrol chose > ad= 55m in phose, > >X ~ > S = 55m yr idm als yo, BNO? Gs » 7 im Brotha