Ryerson University

• PCS 125

• Midterm Test – March 10, 2022 Read the following attentively  Ensure that your name and student number are correct in the bubble sheet.  Duration of the exam is 80 minutes.  The exam consists of 12 multiple-choice questions. Answer ALL questions and show all work.  Each multiple-choice question is worth 1 mark.  For each multiple choice question: o You need to show, in the space provided in this booklet, a justification for your answer. If no work or correct argument is shown, the resultant mark may be zero, even if the answer in the bubble sheet is correct. o The work shown in your exam booklet may be checked, at least for one of the questions, selected randomly. o Transfer your choices to the bubble sheet only when you are sure of them. o Some answers may be rounded off.  Pagers, cell phones, watches, and other electronic devices (other than a calculators fitting the description below) must be silenced and placed out of reach. Hats and earphones are not permitted. If a phone rings, its owner is responsible for disrupting the exam and the phone will be confiscated or the owner will be asked to leave the room resulting in a zero on the test.  Sharing of pencils, erasers and calculators is not permitted.  Talking to another student or glancing over another student’s paper is not permitted and may result in a charge of academic misconduct.  The calculator models allowed for the test are either Sharp EL-546 or Casio FX-991 (or similar models). If you are found to have another type of calculator, it may be confiscated for the duration of the test.  The exam booklet has a total of 11 pages. You are responsible for checking that you have all pages.  You may not leave the exam room during the final 15 minutes of the exam. You may detach the formula sheet on the last page. Please Print Clearly: Student:_______________________________ _________________________ Last Name First Name Student Number: __________________________ Student Section: _______________ Please insert in the circle the initial of your family name Sign here to signify you read the instructions Version A – Please bubble ‘A’ under version on the bubble sheet This study source was downloaded by 100000859607764 from CourseHero.com on 07-30-2023 07:27:18 GMT -05:00 https://www.coursehero.com/file/183691671/PCS125-Midterm-Test-solution-2022VersionApdf/ P a g e | 2 2 | P a g e [This page is intentionally blank and can be used for calculations] This study source was downloaded by 100000859607764 from CourseHero.com on 07-30-2023 07:27:18 GMT -05:00 https://www.coursehero.com/file/183691671/PCS125-Midterm-Test-solution-2022VersionApdf/ P a g e | 3 3 | P a g e 1. A violin is played, producing sound with an initial intensity Ii that increases to a final intensity If. If the final intensity is 10 times the initial intensity (If = 10 Ii), what is the difference in sound level between the final and initial sounds produced by the violin? a) 1dB b) 2dB c) 10dB d) 100dB e) None of the above Solution: The difference in sound level can be written Problem 16.8.2 (Numerical, Easy) 2. A source emits sound with a frequency of 440 Hz and is moving in a straight line with a speed of 24 m/s. An observer driving a car at a speed of 24 m/s is chasing the source along the same line. Assume the speed of sound is 343 m/s. What frequency will be heard by the observer? a) 350Hz b) 550Hz c) 230Hz d) 610Hz e) 440 Hz Solution: The relative velocity between the sound source and the observer is zero, which means This study source was downloaded by 100000859607764 from CourseHero.com on 07-30-2023 07:27:18 GMT -05:00 https://www.coursehero.com/file/183691671/PCS125-Midterm-Test-solution-2022VersionApdf/ P a g e | 4 4 | P a g e the observer is at rest with respect to the sound