Phys 111 Exam 3 November 15, 016 Name Section University ID Please fill in your computer answer sheet as follows: 1) Use your previous answer sheet and start with 41. Note problem number of the second exam starts with 41. ) Make sure that you filled in the circles on the sheet corresponding to the letters or numbers of your name, ID and section. 3) If you use a new answer sheet, follow the following instruction. 4) Fill in the circles on the sheet corresponding to the letters or numbers of your name, ID and section with a # pencil. 5) In the NAME grid, fill in your last name, leave one blank space, then your first name. 6) Write your ID number in the IDENTIFICATION NUMBER section of the sheet. 7) Write your recitation section number in the spaces K, L in the SPECIAL CODES section. Single digits should be preceded by a 0 (e.g. section 1 is written as 01). Note (a) Use g = 9.81 m/s if needed. (b) There are 0 multiple choice problems. (c).0 hour Exam (no one can leave before 9:15 PM). (d) Formula sheets are available (attached at the last two pages). (e) Record sheet is attached after the 0 exam problems. You can take the record sheet with you. DO NOT USE CELL PHONES. Good Luck!!! 1
41. The position of a simple harmonic oscillator is given by t) (0.50 m) cos t where t is in seconds. What is the period of the oscillator? A) 1.0 s B).0 s C) 4.0 s D) 5.0 s E) 6.0 s 4. A mass of 0.150 kg is attached to a spring with a force constant of 3.58 N/m and undergoes simple harmonic oscillations. What is the period of the oscillations? A).57 s B) 0.57 s C) 0.63 s D) 1.14 s E) 1.9 s x( 3 43. Grandfather clocks are designed in a way that the weight at the bottom of the pendulum can be moved up or down by turning a small screw. Suppose you have a grandfather clock at home that runs slow. Should you turn the adjusting screw so as to raise the weight or lower the weight? A) Raise it. B) Lower it. C) It doesn't matter if you raise or lower the weight as long as you displace it by the right amount. D) It doesn't matter if you raise or lower the weight, as long as you displace it with the correct initial velocity. E) Raising or lowering the weight doesn't help. The screw is there so that you can add or take away weight. 44. A mass of 0.150 kg is attached to a spring with a force constant of 3.58 N/m and undergoes simple harmonic oscillations with an amplitude of 7.50 cm. What is the total mechanical energy of the system? A) 0.001 J B) 0.0101 J C) 0.69 J D) 0.134 J E) 0 J
45. A guitar player produces the standing wave pattern on a guitar string shown on the right. The mass of string is m=0.0 kg, the length of the string is L = 60 cm and its tension F=650 N. What is the fundamental frequency of the sound? A. 94 Hz B. 116 Hz C. 136 Hz D. 194 Hz E. 6 Hz 46. A tsunami, an ocean wave generated by an earthquake, propagates along the open ocean at 700 km/hr and has a wavelength of 750 km. What is the frequency of the waves in such a tsunami? A) 0.933 Hz B) 0.00059 Hz C) 1.07 Hz D) 6.76 Hz E) 0.148 Hz 47. A quiet radio has an intensity level of about 0 db. Busy street traffic has a level of about 40 db. How much greater is the intensity of the street traffic compared to the radio? A) about 10,000 times B) about 1000 times C) about 100 times D) about 10 times E) about the same 48. Two in-phase loudspeakers are 3.00 m apart. They emit sound with a frequency of 490 Hz. A microphone is placed half-way between the speakers and then moved along the line joining the two speakers until the first point of constructive interference is found. At what distance from that midpoint is that first point? The speed of sound in air is 343 m/s. A) 0.175 m B) 0.350 m C) 0.500 m D) 0.700 m E) There is no point in that line where constructive interference occurs. 3
49. A motorcycle and a police car are moving toward one another. The police car emits sound with a frequency of 50 Hz and has a speed of 13.0 m/s. The motorcycle has a speed of 7.0 m/s. What frequency does the motorcyclist hear? The speed of sound in air is 343 m/s. A) 51Hz B) 563 Hz C) 566 Hz D) 588 Hz E) 599 Hz 50. You blow into an open pipe and produce a tone. What happens to the frequency of the tone if you close the end of the pipe and blow into it again? A) depends on the speed of sound in the pipe B) you hear the same frequency C) you hear a higher frequency D) you hear a lower frequency 51. Three containers (the right figure) are filled with water to the same height and have the same surface area at the base, but the total weight of water is different for each. Which container has the greatest pressure acting on its base? A) container 1 B) container C) container 3 D) all three are equal E) cannot determine 5. A pipe contains water flowing with a speed of 1.6 m/s. When the pipe narrows to one-half its original diameter, what is the speed of the water? A) 1.6 m/s B) 3. m/s C) 6.4 m/s D) 9.6 m/s E) 1.8 m/s 4
53. Suppose you pour water into a container until it reaches a depth of 1 cm. Next, you carefully pour in a 7. cm thickness of olive oil so that it floats on the top of water. What is the pressure at the bottom of the container? The densities of oil and water are 90 kg/m 3 and 1000 kg/m 3, respectively. The atmospheric pressure is P atm = 1.013 10 5 Pa. A) 1.003 10 5 Pa B) 1.03 10 5 Pa C) 1.04 10 5 Pa D) 1.07 10 5 Pa E) 1.08 10 5 Pa 54. A runner generates power 753 W (=J/s) of thermal energy. If this heat has to be removed by evaporation, how much water does this runner lose in 5 minutes of running? The latent heat of vaporization of water is.6 10 5 J/kg. A) 15 g B) 500 g C) 830 g D) 380 g E) 980 g 55. The world s longest suspension bridge is the Akashikaikyo Bridge in Japan. The bridge is 3910 m long and is constructed of steel. How much longer is the bridge on a warm summer day (30.0 ) than on a cold winter day (-10.00 )? The coefficient of thermal expansion for steel is = 1 10-6 ( ) -1. A) 0.75 m. B) 0.94 m C) 1.41 m D) 1.65m E) 1.87 m 56. A 5.0-g lead bullet is fired into a fence post. The initial speed of the bullet is 50 m/s, and when it comes to rest, half its kinetic energy goes into heating the bullet. How much does the bullet temperature increase? The specific heat of lead is 18 J/(kg K). A) 60 K B) 1 K C) 180 K D) 30 K E) 40 K 5
57. Two strings both vibrate at exactly 819 Hz. The tension in one of them is then increased slightly. As a result, six beats per second are heard when both strings vibrate. What is the new frequency of the string that was tightened? A) 85 Hz B) 813 Hz C) 8 Hz D) 816 Hz E) 798 Hz 58. Object 1 has two times the specific heat capacity and four times the mass of Object. The two objects are heated from the same initial temperature, T 0, to the same final temperature T f. You determine that the amount of heat gained by Object 1 is Q. The amount of heat absorbed by Object will be A) 1Q. B) 8Q. C) 3 4 Q. D) 1 1 Q. E) 1 8 Q 59. A heat transfer of 19 10 5 J is required to convert a block of ice at 15.0 to water at 15. What was the mass of the block of ice? The specific heat of ice is 090 J/(kg K), the specific heat of water is 4186 J/(kg K), and the latent heat of fusion of water is 33.5 10 4 J/kg. A) 1.1 kg. B). kg C) 3.3 kg D) 4.4 kg E) 5.5 kg 60. A 74-kg person drinks a thick milkshake of 305,000 cal. How many stairs must this person climb to work off the shake? The height of the stair is 0.0 cm. (1 cal = 4.186 J). A) 1760 stairs B) 41 stairs C) 35 stairs D) 4400 stairs E) 8800 stairs 6
Record Sheet of Exam # 3, Physics 111, Fall 016 You may fill in this sheet with your choices and take it with you for comparison to the posted answers. 41 51 4 5 43 53 44 54 45 55 46 56 47 57 48 58 49 59 50 60 7
Physics 111, Fall 016: Formula sheet Vectors: A Acos A Asin x y 1 x y tan Ay / Ax A A A Linear Motion: x x f xi v x / t a v / t v v0 at 1 1 x v0t a t v v0 a x x v0 v t Forces: N Fnet mm 1 Fnet F1 F F3 Fi a Fg G i1 m r Weight W mg fk kn fs sn Fx kx Work and Energy: W ( F cos ) d KE mv / PE mgh P work / t Fd / t Fv Etot KE PE PE kx / Linear momentum and impulse: p mv Ft p I Ft p p 0 p f pi x m x / m cm i i i y m y / m cm i i i Uniform Circular Motion: v r / T a v / r c F c mv / r tan v / rg Rotational Kinematics: s/ r / t / t 0 t T / 1 0t t vt r t r 0 ac r Rotational Dynamics: rsinf L 0 Lf Li I miri I L / t L I KE R I / W Gravity: F Gm m r g 1 / G Nm kg 11 6.67 10 / / g 1 PE U Gm m r KE mv / Oscillations about equilibrium: f F kx x Acos( t); vx Asin( t); ax Acos( t) T k 1 1 1 L E KE PE mv kx ka T m g
Waves and Sound: F m P P v f v ; I T L A 4 r n log( AB) log( A) log( B); log( A/ B) log( A) log( B); log(10 ) n (10 db)log( I / I ); I 10 W / m 0 0 1 1 Doppler Effect for moving source: f0 fs (-) source moving towards observer 1 vs / v v0 Doppler Effect for moving observer: f0 fs 1 (+) observer moving towards source v Constructive Interference: d1 d n; n 0,1,,3,... Destructive Interference: d1 d n ; n 1,3,5,... Standing waves on a string of length L = Standing waves in a column of air open at both ends of length L L v v n ; fn n ; n 1,,3,... n n L Standing waves in a column of air closed at one end of length L 4 L v v n ; fn n ; n 1,3,5,... n 4L Beat Frequency: fbeat f1 f n Fluids: M F 5 ; P ; Pgauge P Patm ; Patm 1.01 10 N / m V A P P gh 1 F Vg Buoyant fluid m1 m Conversation of Mass : 1 A1 v1 A v t t 1 1 Bernoulli ' s Equation : P v gy P v gy 1 1 1 Temperature and Heat: 5 TC TF 3 TK TC 73.15; L L0T ; V V0T ; Q mct 9 4 8 4 Q ml ; Q ml ; Q / t kat / L; Q / t eat ; 5.67 10 W( m K ) fusion f vaporization v Ideal Gases: 3 PV nrt Nk T; n N / N m / ( mass per mole); R 8.31 J( mol K); k 1.3810 J / K B A B 3 1 3 3 3 NA 6.010 molecules / mole; KEav ( mv ) av kbt; U nrt NkBT Thermodynamics: U Q W; W PV ; CV 3 R / ; CP 3 R / ; CP / CV 5/ 3 W Qh Qc Qc Tc Qh Qc e 1 1 ; COP ; Air Conditioner COP Qh Qh Qh Th W W Q Qh Qc S ; Stotal 0 T T T h c