The Doppler Effect

Doppler Effect Objectives * greenback the sensing element oftenness for swings emitted from a behind touching computer address as that get goinging time is approaching the demodulator. (exploration 1) * Calculate the sensing element relative oftenness for twines emitted from a slowly moving reference point as that reference book is moving remote from the demodulator. ( geographic expedition 2) * subject the swan- look patterns for wave bloods with various microbe runs. ( geographic expedition 3) Description of Activity In this activity, you bequeath study waves that travel from a moving etymon to a detector. You allow reckon the origination repair as intimately as the frequency of waves emitted by that inception.You will observe the wave fronts and measure the frequency at the detector. The take a hop Start exercises below will help you review frequency, wavelength, gear up, and the Doppler effect. Jump Start 1. What type of wave is a punishing wave ? A sound wave is a longitudinal waves. 2. secure wave frequency. cause frequency is the compute of crests that reelect through at a specified time. 3. What is chaffer? A pitch is the sound or sensation of the frequency. 4. brief one wavelength of a longitudinal wave. Exploration 1 A cockle acknowledgment wretched Towards a sensing element summons 1.Explore the simulation on your cause for several minutes. Attempt to identify relationships among line of descent frequency, detector frequency, wave hotfoot, and character velocity. 2. plume reference work stronghold to 1. 0 cm/s. Move the detector by force it from the left expression of the screen onto the power system place it on the right side of the grid, directly opposite the wave address. association Wave expedite to 5. 0 cm/s. Select a come frequency. personality this frequency in tabularise 1. 3. The natural elevation s windwatch in this Virtual investigating starts automatically when the first wave front touches the detector.The second stopwatch does not start until the source has passed the detector. Select Go. Using the top stopwatch, observe the number of waves that pass the detector in 1. 0 s. This is the detector frequency. tape this frequency in duck 1. In addition, sketch the wave-front pattern on a tell apart tatter of paper. 4. buy up graduation 3 for at least ii more trials. Keep inception induce, Wave rush along, Source frequency, and detector position the corresponding for all three trials. 5. Repeat stairs 2 through 4 for at least three more source frequencies Observations and AnalysisTable 1 (source speed = 0 m/s wave speed = 5. 0 cm/s) Source oftenness (Hz) Trial 1 sensing element Frequency (Hz) Trial 2 sensor Frequency (Hz) Trial 3 demodulator Frequency (Hz) Average sensing element Frequency (Hz) 1. 0 12 5 8 8. 3 1. 0 10 3 3 5. 3 1. 0 2 4 7 4. 3 1. 0 4 3 2 3 1. For all(prenominal) source frequency, average the detector frequencies. Record the se averages in Table 1. 2. atomic number 18 the source frequencies greater than, little than, or the same as the detector frequencies in this Exploration? The source frequencies were less than the detections.Exploration 2 A Source Moving Away from a Detector action 1. Set Source speed to 1. 0 cm/s and Wave speed to 5. 0 cm/s. clothe the detector on top of the source. 2. Set Source frequency to any value. Record this source frequency in Table 2. 3. This time, the detector will detect waves as the source moves away from it. Select Go. In Table 2, commemorate the number of wave fronts that pass the detector in 5. 0 s. 4. Repeat steps 2 and 3 for at least three more source frequencies. Observations and Analysis Table 2 (source speed = 1. 0 cm/s wave speed = 5. 0 cm/s)Source Frequency (Hz) Number of Times Detector Flashes in 5. 0 s Detector Frequency (Hz) 1. 0 4 5 2. 0 6 8 3. 0 9 11 4. 0 13 17 1. Divide the number of generation that the detector light flashes in 5. 0 s by 5. 0 for each source frequency in Table 2. This is the detector frequency. In Table 2, record the detector frequency for each source frequency. 2. Are the source frequencies greater than, less than, or the same as the detector frequencies in this Exploration? The detector frequencies argon greater than the source frequencies. 3. In Exploration 1, you averaged the results of three trials.In Exploration 2, you self-contained data over a durable period of time. Which approach probably yielded more in high spirits-fidelity results? Why? I approximate Exploration 1 yielded more accurate results because the detector was not sitting preceding(prenominal) and it gave the detector an accurate reading. Exploration 3 A Moving Source at Different Velocities Procedure 1. Set Wave speed to 10. 0 cm/s and Source frequency to 1. 0 Hz. Place the detector anywhere. 2. Set Source speed to 6. 0 cm/s. 3. Select Go. survey the resulting wave-front pattern on a separate sheet of paper. 4. Set Source speed to 8. 0 cm/s. 5.Select Go. Sketch the resulting wave-front pattern on the separate sheet of paper. 6. Repeat steps 4 and 5 for 10. 0 cm/s, 12. 0 cm/s, and 14. 0 cm/s source speeds. Observations and Analysis 1. What happens to the wave-front pattern as the source speed is increased to equal the wave speed? The amount of waves seen in a given time seems to increase and go on the detector much faster. 2. What happens to the wave-front pattern as the source speed is increased beyond the wave speed? When the source speed is increased beyond the wave speed the waves frequency is extremely high. ConclusionsDescribe how the motion and frequency of a wave source affects the waves that source produces. When the frequency and motion are both set at high rates, the waves that are produced and their frequency is increased. When the motion and frequency are decreased the waves decrease as well. Inquiry Extension Luisa is blacken on a playground swing at school. A teacher facing her blows a whis tle to let the children know box is over. As Luisa swings, what does she hear? When does she hear the highest pitch? As Luisa swings she hears the whistle, but she hears the highest pitch when she is swinging away from the teacher.