103 Fa22 Exam 3 A no answers

ID Code: A Name: ________________________________________ Section #: _____________ TA Name: ______________________________________ Fill in your name, student ID # (not social security #), and section # (under ABC of special codes) on the Scantron Sheet. Be sure to fill in the letter for the ID code at the top of this page for the first question. This determines which version of the test you took. Make sure your exam has questions 2 through 16 and 7 total pages (plus one blank page for you to work on). Physics 103 Midterm 3 – November 22, 2021 In this exam booklet, circle the letter of the choice that best completes the statement or answers the question. Also mark this answer on your Scantron sheet. Be sure to do both . Most importantly MAKE SURE YOUR SCANTRON ANSWERS MATCH THOSE YOU SELECTED IN YOUR TEST BOOKLET. IF THERE IS A DISCREPENCY, THE SCANTRON ALWAYS WINS. Possibly useful information: g = 9.8 m/s 2 M (mega) = 10 6 Circumference of a circle = 2 πr k (kilo) = 10 3 1 hour = 3600 seconds m (milli) = 10 -3 v sound = 340 m/s μ (micro) = 10 -6 ρ water = 1000 kg/m 3 n (nano) = 10 -9 Assume all these values are the correct one unless different values are specific in a question. ____ 1. Please be very careful with the first question: ENTER THE ID CODE AT THE TOP OF THIS PAGE. a. A ß This is your exam code b. B c. C

Page 2 of 8 ____ 2. (8 pts) A mass is attached to a vertical spring which executes simple harmonic motion between two points A and B. Where is it located when its kinetic energy is maximum. A. At either A or B B. Quarter of the way between A and B, measured from either A or B C. Midway between A and B D. None of the above E. Impossible to say from the information given. ____ 3. (8 pts) A pendulum of a grandfather’s clock is 1.5m long. It’s period on earth is closest to A. 1 second B. 1.5 seconds C. 2.5 seconds D. 2 seconds E. 0.1 seconds ____ 4. (8 pts) Assume the speed of sound is 340 m/s. One stereo loudspeaker produces a sound with a wavelength of 0.68 meters while the other speaker produces a sound with a wavelength of 0.65 meters. What would the resulting beat frequency be? A. 23 Hz B. 3 Hz C. 511.5 Hz D. 11,333Hz E. 0.3 Hz

Page 4 of 8 ____ 7. (8 pts) A string tied at both ends produces the standing wave shown above. The speed of the waves in the string is 2 m/s. What is the frequency of the standing wave shown above? A. 0.25 Hz B. 0.5 Hz C. 1 Hz D. 2 Hz E. 4 Hz ____ 8. (8 pts) Two fire trucks have sirens that emit waves of the same frequency. As the fire trucks approach a person the person hears a higher frequency from truck X than from truck Y. Which of the following statements about truck X can be correctly inferred from this information. A. It is traveling slower than truck Y. B. It is closer to the person than truck Y C. it is speeding up, and truck Y is slowing down D. truck X has exploded E. Its wavefronts are closer together than truck Y ____ 9. (8 pts) A mosquito's buzz is often rated with a decibel rating of 40 dB. Normal conversation is often rated at 60 dB. How many times more intense is normal conversation compared to a mosquito's buzz ? A. 400 B. 20 C. 100 D. 200 E. 2

Page 5 of 8 ____ 10. (8 pts) At what depth within a salt water solution will the gauge pressure be equal to three times the atmospheric pressure? Take the density of salt water to be 1100 kg/m 3 and atmospheric pressure to be 101 kPa. A. 37.5 m B. 0.8 m C. 9.4 m D. 100 m E. 28.1 m The next two questions refer to the following situation: The diagram below shows a fluid flowing through a pipe at two points P 1 and P 2. Assume the fluid is nonviscous and incompressible. Water occupies the lower section of the pipe shown in the shaded part of the diagram. ____ 11. (8 pts) If the cross-sectional area A 2, is 1/5th of of the cross-sectional area A 1, then the speed v 2 must be : A. 10 times bigger than v 1 B. 10 times smaller than v 1 C. 5 times bigger than v 1 D. 5 times smaller than v 1 E. the same as v 1 ____ 12. (8 pts) Assume A 2 is 2.0 cm 2 and v 2 is 10 m/s, while A 1 is 10.0 cm 2 and h=0.5 meters. What is the density of the fluid that flows in the pipe above the water? You can ignore pressure difference due to depth in the fluid that flows in the pipe, but not in the water. A. 10,000 kg/m 3 B. 20 kg/m 3 C. 2.4 kg/m 3 D. 150,240 kg/m 3 E. 102 kg/m 3

Page 7 of 8 ____ 16. (8 pts) An object is traveling on a trajectory shown in the direction shown. The object could be speeding up, slowing down, or moving at constant speed at any of the points indicated. Use the following vectors to determine which statement below is TRUE ? A. If the object is moving with constant speed at point 3, its acceleration may be in the direction of vector S. B. If the object is moving with constant speed at point 4, its acceleration could be zero. C. If the object is slowing down at point 1, its acceleration may be in the direction of vector U. D. If the object is speeding up at point 5, its acceleration may be in the direction of vector O. E. None of the above is true.

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