Physics 140 Winter 2014 Third Midterm Exam April 10 2014 Form 1 SQL uT O S Your name First Last M E A4 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 yout 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 2 2 0 v0t t x x vt at 2a x xo 2 vx at 0 0 I2 2 wot o co coo at W0z 2a O Rw v Ra at dv dt 7 7 v R arad Oo Vpjc VNB VB C continued on the next page Table 9 2 Moments of Inertia of Various Bodies c Rectangular plate b Slender rod a Slender rod axis tlirotisth one end axis through center I I ML G 2 ML I 2 M R3 R axis along edge 2 1 2 M a ti Solid sphere g Thin walled hollow 0 Solid cylinder e Hollow cylinder 1 d Th in reet irlgu tar plate axis through center I 1 Thin walled hollow sphere cylinder 2 Wa 1 2 MR I 9 Edoi i n I continued from the previous page m fr d I mlrl m2r2 2 1 CM Md 1r 2 m 1 Gm Fg Fk 2GM r 2 1 pd pO pgd Vesc UkN W F d j L rxp to 2 Vorb GM r b B p mv Jdt avert J r 2 m m r 1 F dPE Lc rcM 1 2 m 1 EPE 9 TKE mv 2 1w 2 RKE 1 2 r 2 m 1 Gm GPE v 2 EPE k 2 TKE RKE GPE pfluidVdisplacedg v 2 A A v 1 2 pvi pgy 2 P2 pgy2 pv2 P1 Pa x 5 i0 1 013 atm Patm 1 3 Pwater 1000 kg rn g 9 8m s 2 fkg N m G 6 67 x 10h1 2 RE 6 38x 10m ME 5 7 x 1024 kg TKEf RKEf GPEf EPEf 1 An anchor initially lies on the deck of a barge floating in a sealed dock The anchor is then thrown overboard and sinks to the bottom of the dock What happens to the barge with respect to the waterline and to the level of water in the dock with respect to the shore as a result of this event a b c d c 4 2 J Barge rises water level rises Barge sinks water level drops Barge rises water level stays the same Barge sinks water level rises Barge rises water level drops FBI T 1 E rt vvi cLc S 14or e tt4 kj aktd y 1 iDe 0 T Lre 0 oLFer Can t fr fte C4v i 3 i t 2L t4 Cr r cLA41e Qw 1 Lt io Lru tie 4L yt V VA dptaced 4 1 A 4A tke eL9rL L4A tfl J vi L ke 0 e v w t 4 v me 4 r i 1 T 4 tke Itkc t ie vj ve VA So t 4v 4 1 Skfjj e 0 o tte te Lr T eido o r 1 e Fr tt M k1 v ACe h L e 2 Consider five massless rigid disks shown below Each disk is subject to one or several forces as shown The arrows indicate where each force is applied as well as the direction of each force However the arrows do not represent the magnitude of each force and magnitudes can be adjusted if possibly be in static necessary but cannot be made equal to zero Which of these disks equilibrium may I I A e vec t D 4 S C C e bJ e r4 V C C E 1 1f fio 3 Planet X has four times the mass and two times the radius of the Earth How does g on planet X compare to g on Earth a gx gJ 4 b gx gW 2 gx gE d gx e gx g 4 p t zE V i2 E 4 A hollow sphere is held below the surface of a freshwater lake by a cord anchored to the bottom of and its mass is 200 kg What is the tension in the cord 3 the lake The volume of the sphere is 0 5 m Ignore the mass and the volume of the cord a b c d e 1960N 2940N 4900 N 6860 N 7840 N U Tz F cq4o length 12 5 Four forces are applied perpendicularly to a rigid horizontal rod of negligible weight and the cm at points A B C and D as shown in the figure The arrows indicate only the direction of forces and do not represent their magnitudes the magnitudes are not necessarily the same The rod is distances between these four points are as follows AB 3 cm BC 5 cm and CD 4 cm The in static equilibrium Force A is 14 N and force B is 20 N What is force D a 2 N 3N c 4N D C e 6N C t C o 5 6 A rock is launched vertically upward from the surface of an airless non rotating planet of radius R with an initial velocity equal to half the escape speed from the planet What is the maximum distance from the center of the planet the rock will reach a 5R 4 4R 3 Cvw1i ta i4c c 3R 2 d 2R e 4R M f 1V 4 2 GMp tr vi 2 n sc GM 8 7 i tee I tve L e o e44 m 1 CmMp I OcJ dO ep er q oItt y 1 11 1 W ettl Xr 5t j d f 7 3 2Mr A4 Rp P 4 iP 3 0 g on a 7 A frictionless sliding hockey puck and two rolling objects a hoop and a disk are movin three objects horizontal surface side by side with the same initial speed v toward an inclined plane All g Ignore have the same mass M Both rolling objects have the same radius R and roll without slippin air resistance Which object will go the furthest up the incline a Puck j Hoop c Disk d Hoop and disk tie e All three objects reach the same maximum height all have same initial speed v LJ hoop puck disk I t av C mr i …