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.
Select Go. Sketch the resulting wave-front pattern on a separate sheet of paper.
3. Select Go. Sketch the resulting wave-front pattern on the 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.
Observation and Analysis
1. What happens to the wave-front pattern as the source speed is increased to equal the wave speed?
2. What happens to the wave-front pattern as the source speed is increased beyond the wave speed?
Conclusions
Describe how the motion and frequency of a wave source affect the waves that source produces.
Inquiry Extension
Luisa is swinging on a playground swing at school. A teacher facing her blows a whistle to let the children know recess is over. As Luisa swings, what does she hear? When does she hear the highest pitch?
1. To answer the first question, we need to go through the steps of the procedure and analyze the resulting wave-front patterns for different source speeds.
In Step 2, when the source speed is set to 6.0 cm/s and the wave speed is set to 10.0 cm/s, we need to select "Go" and sketch the resulting wave-front pattern. This pattern will show how the wave-fronts propagate from the moving source.
In Step 3, we repeat the process by selecting "Go" again with the same source speed. This allows us to observe any changes in the wave-front pattern compared to the previous step.
We repeat these steps for different source speeds (8.0 cm/s, 10.0 cm/s, 12.0 cm/s, and 14.0 cm/s) to gather more data and compare the resulting wave-front patterns.
2. Now, to answer the second question, we need to analyze the wave-front patterns as the source speed is increased beyond the wave speed.
By comparing the patterns obtained when the source speed is equal to the wave speed and when it is increased beyond the wave speed, we can observe any notable differences. These differences will help us understand how the wave-front pattern changes when the source speed exceeds the wave speed.
Once we have analyzed the wave-front patterns, we can move on to the observations and analysis section.
Observations and Analysis:
1. Based on the data gathered from the steps and the corresponding wave-front patterns, we can conclude what happens to the wave-front pattern as the source speed is increased to equal the wave speed.
2. Additionally, based on the analysis of the wave-front patterns when the source speed is increased beyond the wave speed, we can conclude what happens to the wave-front pattern in this scenario.
Conclusions:
Based on the observations and analysis, we can draw conclusions about how the motion and frequency of a wave source affect the waves it produces.
Inquiry Extension:
To answer the question about what Luisa hears as she swings on a playground swing while a teacher blows a whistle, we need to consider the concepts of frequency, motion, and relative velocity.
As Luisa swings, her motion will impact her perception of sound from the whistle. The frequency of the sound will be affected by the relative velocity between Luisa and the source of the sound.
When Luisa swings towards the teacher blowing the whistle, the relative velocity between them increases, causing the apparent frequency of the sound to be higher. This will result in Luisa hearing a higher pitch.
Conversely, when Luisa swings away from the teacher, the relative velocity decreases, causing the apparent frequency of the sound to be lower. This will result in Luisa hearing a lower pitch.
To determine when Luisa hears the highest pitch, we need to consider the exact dynamics of her swinging and the timing of the teacher blowing the whistle relative to her motion.