Quiz12_16solutions - Quiz 12A Physics 221 Spring 2016...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Quiz 12A Physics 221, Spring 2016 Section: Name: Problem 1. An o ffi cer in his parked cruiser spots a robber 10 meters away. When the police turn on the 400Hz siren, the robber notices the sound intensity is 0.026 W m 2 . If the o ffi cer is seated 1 meter from the siren, what is the intensity he perceives? I 1 = P A 1 and I 2 = P A 2 where A = 4 r 2 I 1 = 4 r 2 2 4 r 2 1 I 2 I 1 = 2 . 6 W m 2 How much energy does the siren emit after 10 seconds of operation? I = P A P = I 4 r 2 P 10 seconds = 326 Joules Problem 2. Determine the observed frequency the robber hears if he runs away at 2.0 m s 2 and the cruiser drives toward him at 10 m s 2 . (Speed of sound = 343 m s 2 ) F L = v + v L v - v s F S v L = - 2 and v S = 10 F L = 410 Hz
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Quiz 12B Physics 221, Spring 2016 Section: Name: Problem 1. An o ffi cer in his parked cruiser spots a robber 15 meters away. When the police turn on the 400Hz siren, the robber notices the sound intensity is 0.026 W m 2 . If the o ffi cer is seated 1 meter from the siren, what is the intensity he perceives?
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern