Name Secion Phsics 1210 Final Exam Ma 2011 v1.0 This es is closed-noe and closed-book. No wrien, prined, or recorded maerial is permied. Calculaors are permied bu compuers are no. No collaboraion, consulaion, or communicaion wih oher people (oher han he adminisraor) is allowed b an means, including bu no limied o verbal, wrien, or elecronic mehods. Sharing of calculaors is prohibied. If ou have a quesion abou he es, please raise our hand. For muliple choice, ou ma choose wo answers, and if one is correc, receive half credi, ec. For full credi on wrien problems, show he full hough process from basic equaions o final resuls. V avg = x x 2 1 = x 2 1 x 1 =x 0 v 0 1 2 a2 a avg = v v 2 1 = v 2 1 v 1 =v 0 a a rad = v2 R = 4 2 R T 2 v 1 2 =v 0 2 2a x 1 x 0 V sphere = 4 waer =1000 kg/m 3 3 R3 ice =920 kg/m 3 2.2lbs=1 kg 1mi=5280 f=1709m 1Calorie=4200 J Work/Energ F=m a F spring = kx F f = F n W= F s W= K U s = 1 U 2 kx2 P= W g =mg =F v Momenum/Impulse p=mv J= mv =F X cm = m i x i Angular Moion m i Power ro = 1 = 0 0 1 2 2 1 = 0 1 2 = 0 2 2 1 0 W grav = U F= du dx 2 =I I= i m i r i I parallel =I cm Md 2 = r F=rF sin W= K= K ro = 1 2 I 2 K oal = 1 2 mv 2 cm 1 2 I cm 2 = d d = d d s=r v=r a an =r a rad = 2 r Gravi: G=6.67x10-11 N m 2 /kg 2 L= r p=r mv=i L= F g = G M M 1 2 r 2 U g = G M M 1 2 P 2 = 4 2 a 3 r GM Periodic Moion f = 1 =2 f T pendulum: = g l = k m phsical pendulum= gdm I x= A cos v= A sin a= 2 A cos damped moion: x=a e b/ 2m cos ' Fluids Sound '= k m b2 4m 2 P= df da pressure max =BkA p 2 p 1 = g 2 1 1 A 1 v 1 = 2 A 2 v 2 p 1 g 1 1/2 v 1 2 = p 2 g 2 1/2 v 2 2 Mechanical Waves v= f x, = A cos kx k=2 / =2 f =vk v wave onsring = F / f fundamenal = 1 F 2L f n=n v 2 2 2L =nf I 1 1 n=1,2,3,... I= P 4 r 2 B sound inensi = 10 db log I I 0 v longiudnal= B f n open pipe = nv 4L v ideal gas= R T M f n closed pipe = nv 4L I = r 2 2 2 2 r 1 v solid rod = Y f bea =f 1 f 2 I sound inensi = P 2 max 2 v f L = v v L v v S f S
1. (10 ps) A child sanding on a bridge hrows a rock sraigh down. The rock leaves he child's hand a =0. Which of he graphs shown here bes represens he posiion of he sone as a funcion of ime? (Ignore air resisance) A B C D E 2. (10 ps) A girl pulls wo oher children in a wheeled car up a hill a increasing speed. The car moves uphill because A. he girl pulls harder on he car han he car pulls back on her B. he force he girl applies o he car is sronger han he force of gravi on he car *C. he forward force from saic fricion on he girl is larger han he backward force from rolling fricion and gravi on he car D. he ne fricional force and gravi force is negaive bu smaller han he ne force of her pull which is he larges force acing on he car E. he girl is brillian and has invened ani-gravi 3. (10 ps) Saring from res, a box of mass M is pushed across a fricionless floor b a force F. I ends up wih a kineic energ K. If ou waned o double he final kineic energ of he box b changing one hing, ou could (circle one or more rue answers) *A. double he force o 2F B. double he mass of he box o 2M *C. double he disance ha ou push he box while pushing wih force F D. double he amoun of ime ou push while pushing wih force F E. none of he above will work 4. (10 ps) A block of ice slides o he righ a consan speed across a level fricionless floor. Draw a labeled free bod diagram for he block. 5. (10 ps) A hollow ball and a solid ball of he same mass and radius iniiall have he same oal kineic energ when he sar rolling up he same ramp of consan angle above he horizonal. A. The boh reach he op of heir maximum heigh a he same ime. B. The boh sared wih he same ranslaional speed C. The boh sared wih he same angular speed *D. The boh go he same heigh up he ramp before coming o a sop. E. The boh have he same momen of ineria. 6. (10 ps) A car rounds a curve on a normal da in he usual wa a consan speed on a fla road. As i does so *A. saic fricion produces a cenripeal force B. is kineic energ is changing C. is angenial speed is zero D. kineic fricion produces a angenial force E. is cenripeal acceleraion is changing magniude
7. (10 ps) A box of mass m slides along a surface ha is inclined a an angle from horizonal. The coefficien of kineic fricion beween he box and he surface is k. How would he magniude of is acceleraion if i slides up he incline compare o he magniude of is acceleraion if i slides down he incline? A. The magniude of is acceleraion would be greaes if i slides downhill. *B. The magniude of is acceleraion would be greaes if i slides uphill. C. I would accelerae wih he same magniude when sliding in eiher direcion. D. The ranking depends on he specific values of k and. 8. (10 ps) A perfec Hooke s law spring hangs a res from a rigid suppor. A meal ball of mass M is aached o he boom end of he spring and released from res, hereafer oscillaing up-and-down in simple harmonic moion. If his scenario were repeaed on anoher plane whose graviaional acceleraion were smaller han 9.8 m/s 2, he mass would oscillae: (selec he correc choice from each four liss) A. wih a higher frequenc. wih a lower frequenc. *a he same frequenc. B. wih a larger ampliude. *wih a smaller ampliude. a he same ampliude. C. wih a faser maximum speed. *wih a slower maximum speed. wih he same maximum speed. 9. (10 ps) Which one of he following saemen regarding work and energ is correc? A. The work done b an pe of force can be represened b a poenial energ funcion B. Fricional forces alwas do negaive work C. When poenial energ increases, he corresponding conservaive force mus have done posiive work D. When poenial energ increases, kineic energ mus decrease *E. None of he above 10. (10 ps) Two cars wih speed v 1 >v 2 bu same masses (m 1 = m 2 ) collide head-on and sick ogeher afer he collision. A. The oal kineic energ before he collision is he same as he oal kineic energ afer he collision B. The oal momenum before he collision is larger han he oal momenum afer he collision C. Boh cars sop afer he collision *D. The cars do no sop afer he collision bu move along he iniial raveling direcion of he car wih speed v 1 E. The cars do no sop afer he collision bu move along he iniial raveling direcion of he car wih speed v 2 11. (10 ps) A chunk of space rock fall o he earh from he disance of he moon. As i is falling, A. The objec s kineic energ decreases *B. The objec s graviaional poenial energ decreases C. The objec s angular momenum increases D. The objec's momenum sas he same E. The objec s oal mechanical energ decreases
12. (10 ps) The diagram below shows a snapsho a one ime of a sring wih a purel ransverse wave raveling along i o he righ. Eigh poins on he sring are indicaed. (The poins are poins on he sring, no phases of he wave. The move up and down wih he sring, no o he righ.) A. Which poins have a speed of zero? C,g B. Which poins have an acceleraion of zero? (a, e) C. Which poins are moving upward ( )? (d, e, f) D. Which poins are moving downward ( )? (a, b, h) E. Which poins are acceleraing upward? (f, g, h) F. Which poins are acceleraing downward? (b, c, d) 13. (10 ps) An airpor worker near a je experiences a sound inensi 16 imes he safe level. In order o decrease he his sound exposure o he maximum safe level he needs o increase his disance from he je b a facor of A. 2 *B. 4 C. 8 D. 16 E. 32 14. (10 ps) The Bernoulli equaion is reall a saemen of *A. energ conservaion for a moving fluid B. Newon's hird law, i.e., acion and equal reacion C. Conservaion of linear momenum D. F=ma as applied o a fluid E. he coninui principle for mass conservaion 15. (10 ps) Shown is a wave raveling along a clohesline. The line is ied a one end and he oher end is ied o a ring free o move on a pole. The ension force remains he same. Which of he following figures show he form of he wave when i ravels back oward he ied end? B A B C D E
16. (30 ps) Survivors of mass m=70 kg from a shipwreck spo a clindrical wooden log wih lengh L=5m and diameer D=1.5m and mass M=600 kg. Give an expression for N, he number of people ha he log can suppor before i is compleel submerged in erms of he oher given consans and an needed consan values. Then compue a value for N. (Assume ha he people are enirel ou of he waer on op of he log).
17. (40 ps) A uniform bar wih mass M and lengh L ress on a fricionless surface and pivos a a poin ha has a disance of d d from he lef end. A bulle wih mass m raveling perpendicular o he rod wih speed v his he bar a he righ end and becomes embedded in i. Express he angular speed of he bar afer he srike using M, L, d, m, and v. v
18. (30 ps oal) A rope of mass M and Lengh L is ied o an immovable wall on one end and he oher end is draped over a pulle and hen a seel ball of mass Q is hung a he end, as picured. You ma neglec he mass of he pulle bu no he mass of he rope. Assume ha he rope does no srech. A. (25 ps) If he rope is plucked like a guiar sring a he wall, give an expression for he ime required for a wave o ravel o he pulle and back o he wall again. Also show ha our expression evaluaes o he correc unis. B. (5 ps) On he diagram, draw in he appearance of he sring if i is vibraing in he hird harmonic (second overone). ½ L Q
H 19. (50 ps) A box of mass M sars from res and slides down a ramp a disance S where here is coefficien of kineic fricion k. I falls off he edge and lands a disance D from he base of he ramp. The dashed boxes show locaions a various poins in he journe. A. (10 ps) Draw a vecor a each of he dashed boxes o show he magniude and direcion of he NET FORCE on he box a an poin. B. (20 ps) Find an expression for v 1, he speed of he box as i goes off he end of he ramp in erms of given variables. C. (20 ps) Find an expression for D in erms of oher givens shown. You ma use v 1 for he speed of he box for he speed a he end of he ramp if ou don' solve par B full. M S D