Physics 140 Fall 2014 Third Midterm Exam November 20 2014 Form 1 Your name First Last 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 sight The exam is closed book You may use three 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 90 minutes long There are 20 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 0 x v0t 7 a r 2 at xo v 2a x 6 6 2 2 o oot at 1 Vx 2 COz 0 Oz U t Oz 0 z 0 2a o v Rco atan dv dt Ra 7 2 amd v R CO R Vpj VB C continued on the next page Table 9 2 Moments of Inertia of Various Bodies a b Slender rod axis throuih one end Slender rod axis throuch center I l 1 f e Hollow cylinder I 2 ML rectangular plate axis along edge 2 1 2 M g Thin walled hollow cylinder Solid cylinder M R2 R d Thin c Rectangular plate axis thioueh center 1 1 2 MR i h Solid sphere i Thin wailed hollow sphere 1 1 MR 2 2 MR R 1 2012 Pewssfl Ecucaiion 00 continued from the previous page ni2r2 2 r 1 1 m 2 I ki Md 1r m 1 Gm Fg 2 Fk kN 1 U j W p m fr d 2 F d B pnuidVdisplacedg A A v 1 v 2 pv P2 pgy2 pv2 2 2 P1 pgyi 1 my 1 t rxF L r x p IC 2 Vorb GA4 r U 112 2GM r Vesc Pd P0 pgd fdt avert 1 m2 7 m m r rcM mlrl 2 Fr dPE dx 2 2 TKE mv 1 1 2 2 RKE r 2 m 1 GPE Gm 5 Pa Patm 1 atm 1 0 13 x i0 3 kg m 1000 Ppurewater 2 g 9 8 mIs kg m G 6 67 x 10 N 2 10 m RE 6 38x 6 ME 5 97x 1024 kg EPE TKE 2 2 1 RKE GPE EPE TKEf RKEf GPEf EPEf 1 A bullet is fired into a door as shown in the diagram the view is from above The door is hinged at a frictionless hinge at the top of the diagram Which of the following quantities of the door bullet system are conserved during the impact before impact v 400 rn s c LI t 1 k C in LOOm a kinetic energy b linear momentum angular momentum with respect to the hinge d both kinetic energy and angular momentum with respect to the hint e both linear momentum and angular momentum with respect to the hinge C 050 7k t dl e 9x c izi 74 T i J LS Ltti GC41 ttL 4 f C aao M 4 CL What is a minimal additional 3 2 A block of wood weighs 210 N and has a density of 600 kg rn downward force required to sink it in fresh water a 35 N b 70N 140N d 210N e 350N F jj 13 E F fcr o J 714 Je F fwd iJ J Ai 3 An ideal fluid flows in the arrangement of tubes below The tube diameters are equal at points 2 and 3 Rank the locations according to the pressure from smallest to largest a P3 P2 PI P1 P2 P3 c P2 P1 P3 d p2 P1 P3 e P2 3 P1 1 3 te fLe tk o i 2 42112 J3 3 A v 2 44 1 A 3 D 1k LEEi r r itt o 4c 12 f 3 4 What is the magnitude of the total angular momentum about the axis perpendicular to the page and passing through the origin 0 for the three particle system shown in the figure a 4 kg m s 2 s 2 8kgm b s 2 12kgm d 24 kg m s s 2 e 6Okgm L x Y 2kg 3k L Sj 2m sn D 1 m rJ4 1 5m 4m s we S L k rI 1 2 i 4 L 14 o L I 5 The tanks in the figure are filled with a fluid In all cases the diameters of the thin cylinders on the left are the same and the diameters of the thick cylinders to the right are the same as well You may neglect the masses of the thin disks on which the masses sit at the tops of the thick cylinders Rank in F 2 4 required to balance the F 1 and F 3 order from smallest to largest the magnitudes of the forces F masses i a F a 3 4 1 F 2 F 1 F 3 2 b 4 3 F 2 F F 1 F F 4 F 1 2 d 3 F 1 F 3 4 e 2 2 F 1 F 3 F L oj Q1t zI A w t 4 F 600 kg 600kg pr 500 kg 500 kg J front r 1443 A Jf 4 A E 7 12 4 i t t 4 OL A A 4 21 1 rn 2112 I i 4 j7i 500 kg 6 Three children each of mass in initially stand at the edge of a merry go round symmetrically spaced The merry go round is a circular disk of mass M and radius R that is initially spinning with the angular velocity w Then the children walk to the center of the merry go round What is the final angular velocity co of the merry go round after they reach the center m M m a b c d 7LL M M 2m M M 4m M M 6m M 1AA k M 3m m WI t J t u tltL Of 4 c 1k J C Ivfz hC 7Lr t I l 4AM t 1 erV A L MR 3 o L M v 7 Four thin uniform rods are suspended by a string as shown All four rods including rod 4 have the same mass rod 4 is just twice as dense In each case the rods are at rest Rank the four situations in terms of the magnitude of the tension force in each string from smallest to largest b c d e i4k 4 T 2 Ti T T 1 T 4 2 T T T 3 T 1 4 T T 2 T 1 4 3 T 3 …