Physics 140 Fall 2013 Final Exam December 13 2013 Form 1 50L JTIOI J5 Your name First Last A4 J C c ic 1K Your UMID number Fill in your name student ID number and form number on the scantron and in the spaces above All cell phones text massaging devices computers and communication devices of any type must be turned off and stowed out of site The exam is closed book You may use four 3 x5 7 5 cm x 12 5 cm notecards both sides You may also use a calculator that cannot communicate with the outside world You cannot share calculators notecards scratch paper exam booklets or scantrons Exam responses must be based on your individual work only You must mark the correct answer on the scantron to get credit for each problem The exam is 125 minutes long There are 26 multiple choice questions All questions are of equal value There is no penalty for guessing At the end of the exam hand in your scantron and show your UM ID Constants and equations you may find useful x xo 7 v t 0 arI2 1 Ox cit 7 i 0 00 2a x xO t at2 2 0 c0 0 0o Ctt 7 7 030 2u 0 0 Rm dv dt Ra 7 7 ra1 i1 R 0 R 1 v 81 V VA Q VA B continued on the next page Tab e 9 2 Moments of Inertia of Various Bodies b Slender rod a Slender rod I 1 e Ilollow 1 Solid cylinder CYlinLler d fh in rectangu ar plate axis along edge c Rectangular plate axis through center axis tlirouh one end axis through center M n 62 I h Solid sphere g Thinwalled hollow cylinder I le J MR 2 I N 4 N 11 I I 2 MR i Thinwalled hollow sphere 2 MI Hi 1 continued from the previous page Im 2 m2r2 r 1 I CM Md 2 t rxF L rxp 10 Pd P0 pgd A v A v 2 2 P2 pgy2 pV2 2 p pgy pv x t Acos cot qt cox 2 2 or g L 2 or mgd Ipjvot U co Wm co 2irf 2n T k 2nL 2 co k ET f F p Fb PfluidVdisplacedg pkN 5 F Gm Jm2Ir 2 Vorb GIVI r 2 1 2GM r vesc F W p iiiv 1 f Pdt avert j 1n2r2 in rCM nz r 5 F I I E g 9 8m1s 2 kg Nm G 6 67 x 10 2 106 X rn 6 38 REartli 1024 kg MEarth 5 97 X 1n2 dPE dx tnv 2 2 5 Pa 1 atm 1 013 x i0 3 Pwater 1000 kg rn Patm RKE 1c02 2 GPE Gm in r 2 EPE kv 2 2 1 GPEI EPE 1 W 00 TKE RKE TKEf RKEf GPEf EFEf 1 Find IXj k h I c 0 d j e 1 A k 2 An air hockey puck of mass iii 0 1 kg is sliding across a horizontal frictionless surface with speed If a constant force of 20 N is applied to the puck by an outside entity in the direction v 20 opposite to its velocity what will the stopping distance be im s a 0 05 m b 0 5 m 1 0 c77aj In 2 0 in e 5 0 in X7 t AKf d S co Fx csC x s c a II2 2F Lie F X r kc x CV C S 3 YOU are playing a guitar and you would like to increase the fundamental frequency of one of the strings by a factor of 2 an octave higher Which of the following strategies will yield the desirable result 1 Replace the string with another one of the same length but oniy a quarter of mass 2 Cut the string s length in half 3 Increase the tension in the string by a factor of four a b c d e Ior2only Ior3 only 2or3only any one of the three a combination of any two of the three t4 zIwe Ot O1 2L J LL T e c9 k LJL CJJi 0 E 4 974 F k m L 1 v t J L 2 14 2 2f Jt esLi 4 Assume that we can model a hockey stick as a uniform rod Consider such an idealized hockey stick lying on the ice which we take to be a frictionless surface Now suppose that a hockey puck slides into the end of the hockey stick and imparts an impulse The puck bounces off i e it does not adhere to the hockey stick Which of the following statements best describes the subsequent behavior of the hockey stick a The hockey stick will rotate about its center of mass b The hockey stick will rotate about is left end point c The hockey stick will slide forward d The hockey stick will slide forward and rotate about its center of mass e None of the above I L I 4 U A 4 L4 Le L t L 3 1Vf Ic3 Q 7 r 5 An object moving in the xy plane is acted upon by a conservative force described by the potential energy function PE x y where a is a constant Find the coffesponding conservative force 3a a x y a a b a j 2x v 2 a c i j x y i j e t j iiec i ti 2y 2 3a eKe fe ce tiI at a a d 2x 2 3a tle z 3a AMz2e FJ aiJiae A vti L PE A7 LdL t 7 4 J 4 1 3 cPE 30 XL 3 0 4 y t L Z 3o 6 A string with both ends fixed is vibrating in the standing wave pattern shown in the diagram If the waves have speed v 200 ni s and frequency 440 Hz how long is the string Nod c a 0 12rn 0 68 rn c 0 73 m d 1 36m e 8 57 m I4 ZI I I I 2 2 1 Cf L L 2 xktinode 7 You are 10 km away from a rock concert At this distance you can barely hear the music but you Suppose that you want to 2 have a sensitive instrument that tells you the sound intensity is i0 W m 2 the threshold of pain How close must enjoy the music at a respectable level with intensity I W m you get to the sound source The sound source can be considered as a point source j3 16 m b 10 Om c 31 6m d lOOm e 316m J Ow eJL I ct 12 2 r I I q 8 The graph shows the gravitational potential energy of an object as a function of its horizontal position x The object is a solid cylinder of mass in 100 kg and it rolls without slipping When the object is at position x 30 m and rolling to the right its speed is v 10 mIs Will the object make it …