PHYSICSBOWL APRIL 1 APRIL 15, 2010

Size: px

Start display at page:

Download "PHYSICSBOWL APRIL 1 APRIL 15, 2010"

Cory Atkins
5 years ago
Views:

1 PHYSICSBOWL APRIL 1 APRIL 15, QUESTIONS 45 MINUTES The ponor of the 010 PhyicBowl, including the American Aociation of Phyic Teacher and Texa Intrument, are proiding ome of the prize to recognize outtanding high chool phyic tudent and their teacher through their performance on thi year contet. School compete in one of 15 region, each with two diiion. o o Diiion 01 i for tudent taking phyic for the firt time (een if that firt coure i AP Phyic). Diiion 0 i for tudent taking a econd coure in phyic or anyone wihing a challenge. A chool' team core in each diiion i the um of the fie highet tudent core in that diiion. A chool may compete in either or both diiion. INSTRUCTIONS Anwer heet: Write and bubble-in the following REQUIRED information on your anwer heet: Your Name Your School CEEB code (gien to you by your teacher) Your Teacher AAPT Teacher code (gien to you by your teacher only one code per chool!) Your Region (gien to you by your teacher) Your Diiion (01 for firt-year phyic tudent, 0 for tudent in a econd phyic coure) If ALL of thi information i not properly bubbled, you will be diqualified from indiidual award a your official core will be a zero. Your anwer heet will be machine graded. Be ure to ue a # pencil, fill the bubble completely, and make no tray mark on the anwer heet. Quetion: The tet i compoed of 50 quetion; howeer, tudent will be required to anwer only 40 quetion. Anwer hould be marked on the anwer heet next to the number correponding to the number of the quetion on the tet. Diiion 01 tudent will anwer only quetion Number on the anwer heet hould remain blank for all Diiion 01 tudent. Diiion 0 tudent will anwer only quetion Number 1 10 on the anwer heet hould remain blank for all Diiion 0 tudent. Calculator: A hand-held calculator may be ued. Any memory mut be cleared of data and program. Calculator may not be hared. Formula and contant: Only the formula and contant proided with thee intruction may be ued. Time limit: 45 minute. Score: Your core i equal to the number of correct anwer (no deduction for incorrect anwer). If there are tie core, the entrie will be compared, from the end of the tet forward, until the tie i reoled. Thu, the anwer to the lat few quetion may be important in determining the winner, and you hould conider them carefully. Good Luck! If your exam i a photocopy or preiouly opened, your chool i in iolation of US copyright law and the contet rule. Do Not Open Thi Booklet Until You Are Told to Begin. Copyright 010, AAPT

2 ATTENTION: All Diiion 01 tudent, START HERE. All Diiion 0 tudent kip the firt 10 quetion and begin on # The ery firt PhyicBowl took place in Approximately how many econd ago did tudent compete in thi firt contet? 10 (B) 5 10 (C) 7 10 (D) 9 10 (E) Which of the following i NOT a ector quantity? Acceleration (B) Aerage Velocity (C) Linear Momentum (D) Potential Energy (E) Force. The following three meaurement of length are gien: L 1.05 m, L 6.11 m, and L 89. 6m. What i the um of thee meaurement uing rule of proper ignificant digit? 10 m (B) 11 (C) 117. (D) m (E) m 4. Which of the following relationhip correctly rank the three gien peed from leat to greatet? 4 The peed are gien a cm , Mm , and km week day 1 (B) 1 (C) 1 (D) 1 (E) When computed with proper MKS unit, the Unieral Ga Contant diided by Boltzmann contant i equal to the peed of light. (B) Planck contant. (C) Aogadro number. (D) the permittiity of free pace. (E) the Unieral Graitational contant. 6. Which of the following tatement i mot cloely aociated with Newton Third Law of Motion? What goe up mut come down. (B) For eery action force, there i an equal but oppoite reaction force. (C) An object at ret remain at ret. (D) The acceleration of an object i directly proportional to the force acting on the object but inerely proportional to the ma of the object. (E) The Uniere tend toward diorder. Diiion 01 only Diiion 01 only

7. A mall object i thrown traight downward on Earth with an initial peed of 1.0 m from a poition 10.0 m aboe the ground. Ignoring air reitance, the peed of the object when it reache the ground i 18.

3 7. A mall object i thrown traight downward on Earth with an initial peed of 1.0 m from a poition 10.0 m aboe the ground. Ignoring air reitance, the peed of the object when it reache the ground i 18.4 m (B) 14.6 m (C) 14.0 m (D) 1. (E) 1.0 m The following information relate to Quetion 8 and 9 : A ma i connected to the end of a pring and undergoe imple harmonic ocillation. The graph proided how the poition of the ma a meaured from the floor a a function of time. 8. What i the period of the ma ocillation (in unit of econd)?. 0 (B) 4. 0 (C) 5. 0 (D) 8. 0 (E) What i the amplitude of the ma ocillation (in unit of meter)? 1. 0 (B). 0 (C). 0 (D) 4. 0 (E) A particle trael at a contant peed around a circular path of radiu R. If the particle make one complete trip around the entire circle, what i the magnitude of the diplacement for thi trip? R (B) R (C) R (D) R (E) 0 ATTENTION: All Diiion 01 tudent, continue through quetion 40. Diiion 01 only Diiion 01 only

4 ATTENTION: All Diiion 0 tudent, START HERE. Number 1-10 on your anwer heet hould be blank. Your firt anwer hould be for # Conider the motion of an object gien by the elocity. time graph hown. For which time() i the acceleration of the object equal to 0 m? Only at time (B) Only at time (C) Only at time t. 0 (D) At time t. 0 and t 5. 0 t 5. 0 (E) At time t. 0, t 5. 0, and t 8. 0 t A cientit et up an experiment with a proton of charge Q and ma M being placed near a helium nucleu ( proton and neutron) of charge Q and ma 4 M. The object are each releaed from ret and begin to moe. From the cientit point of iew, which choice bet decribe the object that experience the greatet magnitude of electric force from the other and which object experience the greatet magnitude of acceleration? Ignore graity. Larget magnitude of force Larget magnitude of acceleration The helium nucleu The helium nucleu (B) The helium nucleu The proton (C) The proton The acceleration are equal (D) The force are equal The acceleration are equal (E) The force are equal The proton 1. The Large Hadron Collider (LHC) i the larget particle accelerator in the world. To which of the following countrie would you hae to trael in order to iit the LHC? Germany (B) Italy (C) Switzerland (D) United State (E) Ruia 14. What temperature change on the Kelin cale i equialent to a 7 degree change on the Celiu cale? 00 K (B) 7 K (C) 46 K (D) 7 K (E) 9 K Diiion 01 & 0 4 Diiion 01 & 0

5 15. Three block, labeled A,B, and C, remain at ret on a table. The magnitude of the graitational force on each block i indicated on the figure. What i the magnitude of the contact force on block C from block B? 1.0 N (D) 1.0 N (B) 6.0 N (E) 1.0 N (C) 7.0 N 16. A ma M1 40 kg i at the ery edge of a 6.0 m long plank which i pioted about it center of ma located directly at the center of it length. How far from the center of the plank hould the ma M 80 kg be placed o that the plank remain in tatic equilibrium in a horizontal poition? 0.50 m (B) 1. m (C) 1.50 m (D).00 m (E).00 m 17. A tube of air open at only one end i ibrating in the 5 th harmonic from a tuning fork of frequency 10 Hz placed at the open end. If thi tube of air were to ibrate at it fundamental frequency, what frequency tuning fork would be needed at the open end? 4 Hz (B) 0 Hz (C) 40 Hz (D) 15 Hz (E) 600 Hz 18. Of the following choice, which bet decribe a rapidly rotating neutron tar emitting radiation? Supernoa (B) Quaar (C) Nebula (D) White Dwarf (E) Pular 19. Which i the correct relationhip for the peed ( ) of the following three electromagnetic wae in acuum? The wae are : X-ray, UV ray, microwae. (B) (C) X ray microwae UV ray (D) UV ray microwae X ray microwae UV ray X ray (E) X ray UV ray microwae X ray microwae UV ray 0. A ample of ideal ga i in a container at a temperature of 100 C and a preure of.50 atm. If the olume of the container i 5 L, approximately how many molecule of ga are in the container? (B) (C) (D) (E) Diiion 01 & 0 5 Diiion 01 & 0

1. Which terminology i bet aociated with the amount of energy required to change the phae of a material per unit ma? Thermal conductiity (B) Specific heat (C) Work (D) Latent heat (E) Entropy.

6 1. Which terminology i bet aociated with the amount of energy required to change the phae of a material per unit ma? Thermal conductiity (B) Specific heat (C) Work (D) Latent heat (E) Entropy. A mall and uniform 10.0 kg object float at ret with 75 % of the object ubmerged in a cubical tank containing 50.0 m of water. What i the buoyant force acting on the object? Treat g 10 m N (B) N (C) 100 N (D) 75 N (E) 5 N. A point object of ma M i connected to the end of a long tring of negligible ma and the ytem wing a a imple pendulum with period T. The point object of ma M i now replaced with a point object of ma 4 M. When thi new ytem wing a a imple pendulum, what i it period? 4 T (B) T (C) T (D) T (E) T 4 4. By computing the area under the acceleration. time graph for a fixed time interal of an object motion, what quantity ha been determined for that object? The aerage elocity during the time interal (B) The elocity at the end of the time interal (C) The aerage peed during the time interal (D) The change in elocity during the time interal (E) The elocity at the time midway through the time interal 5. Two point object are launched traight upward with identical linear momentum. Object 1 ha ma M and reache a maximum height H aboe the launch point. If object ha ma M, what i it maximum attained height aboe the launch point in term of H? H (B) 4 H (C) H (D) H (E) 4 H 6. An electron moing in the plane of the page at an angle of 0 to the horizontal enter a region with a contant magnetic field directed horizontally in the plane of the page a hown. At the intant that the electron enter the magnetic field, which bet decribe the direction of the reulting magnetic force on the electron? To the right (B) To the left (C) In a direction not lited here (D) Into the plane of the page (E) Out of the plane of the page Diiion 01 & 0 6 Diiion 01 & 0

7 7. The circuit hown contain a battery (of emf V bat ) with an internal reitance r connected to a rheotat (ariable reitor). When the reitance of the rheotat i increaed, which of the following tatement i true? The terminal oltage (V a V b ) increae. (B) The current through the ammeter in the circuit increae. (C) The power aociated with the internal reitance increae. (D) The potential difference acro the rheotat decreae. (E) None of the aboe tatement i true. 8. Which of the following could produce an enlarged but inerted image of a real object? Place a conerging len at a ditance greater than it focal length from the object. (B) Place a conerging len at a ditance le than it focal length from the object. (C) Place a dierging len at a ditance le than the magnitude of it focal length from the object. (D) Place a dierging len at a ditance greater than the magnitude of it focal length from the object. (E) It i not poible to create the type of image deired. 9. A ball initially at ret fall without air reitance from a height h aboe the ground. If the ball fall the firt ditance h in a time t, how much time i required to fall the remaining ditance of h? 0.5t (B) 0.41t (C) 0.50t (D) 0.71t (E) 1.00t 0. Chromatic aberration from a len i a conequence of polarization. (B) interference. (C) total internal reflection. (D) diffraction. (E) diperion. 1. An object of ma M tart from ret at the bottom of a fixed incline of height H. A peron decide to puh the object up the incline in one of two way with an applied force hown in the diagram. In each of the trial, the object reache the top of the incline with peed. How would the work done by the peron on the block compare for the two trial? Aume the ame contant non-zero coefficient of kinetic friction between the incline and the object for both trial. More work would be done in Trial 1 (B) More work would be done in Trial (C) The work would be equal for both trial (D) It i impoible to determine for which trial there would be more work done without knowing the alue of the peed. (E) It i impoible to determine for which trial there would be more work done without knowing the alue of the coefficient of kinetic friction. Diiion 01 & 0 7 Diiion 01 & 0

8 A rubber ball of ma Quetion deal with the following information:.0 kg falling traight downward hit the ground with a peed of then rebound traight upward with a peed of ground i t Treat g 10 m for thi ituation m and 0.60 m. The colliion time of the ball with the. What i the magnitude of the aerage acceleration (in unit of m ) of the ball while it i in contact with the ground? 1. (B) 6. 0 (C) (D) 1. 0 (E) What i the magnitude of the aerage force (in unit of Newton) exerted by the ground on the ball while they are in contact?. 4 (B) 1. 0 (C) 0. 0 (D) 6. 0 (E) A 4.0 kg object in deep pace moe at a contant elocity of 10 m along the +x axi. The object uddenly explode into equal ma piece. Immediately after the exploion, one piece i now moing directly along the y axi with a peed of 8.0 m. What wa the ize of the impule (in proper MKS unit) proided to thi piece now moing along the y axi from the exploion? 1.8 (B) 16.0 (C) 5.6 (D) 6.0 (E) A point object with ma M. 0kg i attached a ditance R m from the fixed center of a dik a hown in the figure. The dik tart rotating from ret with contant angular acceleration 5.00 rad about an axi perpendicular to the plane of the page through the dik center. After how much time (in econd) i the tangential component of the point object acceleration equal in magnitude to the centripetal component of the point object acceleration? (B) (C) (D) (E) In term of the een fundamental SI unit in the MKS ytem, the unit for capacitance i written a which of the following? A kg m A (B) kg m (C) A A (D) kg m kg m 4 A (E) kg m Diiion 01 & 0 8 Diiion 01 & 0

9 7. A poitiely charged particle i moed in a traight line to the right from poition x 4. 0 m to poition x. 0 m by an external agent. The electric potential at thee poition in pace are V ( x 4 m) 4. 0olt and V ( x m). 0olt. Which tatement i true about the work done by the external agent moing the charge between thee poition and the electric field component parallel to the direction of motion that the moing charged particle experience? Aume the particle i moed at contant peed. The external agent doe no work ince the peed wa contant. (B) The external agent doe negatie work and the electric field i directed to the right. (C) The external agent doe poitie work and the electric field i directed to the right. (D) The external agent doe negatie work and the electric field i directed to the left. (E) The external agent doe poitie work and the electric field i directed to the left. 8. Two object both moe and uniformly accelerate to the right. At time t 0, the object are at the ame initial poition but Object 1 ha initial peed twice that of Object Object 1 ha one-half the acceleration of Object. After ome time T, the elocity of the two object i the ame. What i the ratio of the ditance traeled in thi time T by Object to that traeled by Object 1? 5:6 (B) 4:5 (C) :4 (D) : (E) 1: 9. A trong bar magnet i held ery cloe to the opening of a olenoid a hown in the diagram. A the magnet i moed to the left toward the olenoid, a conentional current through the reitor hown i directed from A to B. What i the direction of the force on the bar magnet becaue of the induced current in the olenoid and which magnetic pole doe the?? in the diagram repreent? Force on magnet Pole of magnet To the right North (B) To the left North (C) To the right South (D) To the left South (E) There i no force It can t be determined 40. A uniform, olid cylinder with a ma M and radiu R i pulled by a horizontal force F acting through the center a hown. The cylinder roll to the right without lipping. What i the magnitude of the force of friction between the cylinder and the ground? F 1 4 F (B) 1 F (C) 1 F (D) F (E) 4 F IMPORTANT: All Diiion 01 tudent STOP HERE. Your lat anwer hould be number 40. Number hould remain blank for Diiion 01 tudent. All Diiion 0 tudent continue to Quetion Diiion 01 & 0 9 Diiion 01 & 0

ATTENTION: All Diiion 01 tudent, STOP HERE. All Diiion 0 tudent, continue to quetion 50. 41. Two phere are heated to the ame temperature and allowed to radiate energy to identical urrounding.

P (B) P (C) 4 P (D) 8 P (E) 16 P 4. A comet moe in an elliptical orbit around the un.

10 ATTENTION: All Diiion 01 tudent, STOP HERE. All Diiion 0 tudent, continue to quetion Two phere are heated to the ame temperature and allowed to radiate energy to identical urrounding. The phere hae the ame emiiity, but one phere ha twice the diameter of the other. If the maller phere radiate energy at a rate P, at what rate will the larger phere radiate energy? P (B) P (C) 4 P (D) 8 P (E) 16 P 4. A comet moe in an elliptical orbit around the un. A the comet moe from aphelion (the point on the orbit farthet from the un) to perihelion (the point on the orbit cloet to the un), which of the following reult i true? Speed of the comet Angular momentum of the comet/un ytem Graitational potential energy of the comet/un ytem Increae Increae Decreae (B) Increae Contant Decreae (C) Decreae Decreae Increae (D) Increae Increae Contant (E) Contant Contant Contant 4. Two ion trael perpendicular to the ame uniform magnetic field. The ion carry the ame charge and hae the ame path radiu in the magnetic field. Which of the following quantitie mut be the ame for the two ion? Ma (B) Speed (C) Charge-to-ma ratio (D) Kinetic energy (E) Magnitude of linear momentum 44. A radioactie ample of ga ha a half-life of 100 econd. If there are initially of thee ga molecule in a cloed container, approximately how many of the molecule remain after a time of 50 econd elape? 500 (B) 190 (C) 1770 (D) 1560 (E) For the ideal RL circuit hown, the reitance i R 10. 0, the inductance i L 5. 0 H and the battery ha oltage bat 1 olt. Some time after the witch S in the circuit i cloed, the ammeter in the circuit read 0.40 A. At what rate i energy being tored by the inductor at thi intant (in Watt)? 0.40 (B) 1.0 (C).0 (D). (E) 4.8 Diiion 0 only 10 Diiion 0 only

46. For the following nuclear reaction, what i the unknown labeled by X? 11 Na X 10 Ne e A proton (B) An electron (C) A neutron (D) An alpha particle (E) A poitron 47.

11 46. For the following nuclear reaction, what i the unknown labeled by X? 11 Na X 10 Ne e A proton (B) An electron (C) A neutron (D) An alpha particle (E) A poitron 47. An open cylindrical container with ery large radiu i at ret a ditance H aboe the ground at the edge of a platform. A tiny hole deelop at the bottom of the container and water from the container quirt out horizontally landing a ditance H from the edge of the platform. For the water to land at thi location, what i the depth of the water L in the container? The figure i not drawn to cale and air reitance i ignored. H 4 (D) H (B) H (E) H (C) H 48. Which of the following waelength (in nm) of electromagnetic radiation will produce photoelectron of the leat kinetic energy if the radiation i incident on a material with a work function of 4.80 ev? 99 (B) 496 (C) 48 (D) 14 (E) A monatomic ideal ga i the working ubtance for an engine that undergoe the cyclic proce (ABCDA) hown in the PV diagram. The procee are all iochoric or iobaric with preure between P 0 and P 0 and olume between V 0 and V 0. What i the efficiency of thi engine? 1 (B) 8 1 (C) 5 1 (D) (E) An object of ma m i initially at ret. After thi object i accelerated to a peed of.40 10, it collide with and tick to a econd object of ma m at ret. Immediately after the colliion, what i the common peed of the two mae?.5 10 (B) (C) (D) (E) IMPORTANT: All Diiion 0 tudent STOP HERE. Your lat anwer hould be number 50. Diiion 0 only 11 Diiion 0 only

PHYSICSBOWL March 29 April 14, 2017

PHYSICSBOWL March 29 April 14, 2017 PHYSICSBOWL 2017 March 29 April 14, 2017 40 QUESTIONS 45 MINUTES The ponor of the 2017 PhyicBowl, including the American Aociation of Phyic Teacher, are providing ome of the prize to recognize outtanding