1. Examine the following Diagram of a wave in a rope and answer the questions that follow.

The diagram is a wavelength from x to y is 4.8m

a) Explain in words, or with a sketch, how the amplitude and one wavelength are measured.
b) Find the wavelength in metres.
c) The time that the waves take to move from point X to point Y is 6.0s. what is the speed of the waves, and what is the frequency?
d) Find the speed and wavelength if the frequency of the source changed to 2.0 Hz. Explain your reasoning.

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
1 month ago

To address your questions, let's break each part down clearly.

### a) Amplitude and Wavelength Measurement

**Amplitude Measurement:**
- **Definition:** The amplitude is the maximum displacement of points on a wave from its rest position (equilibrium).
- **Measurement:** To measure the amplitude, you would look at the vertical distance from the equilibrium position (the midline of the wave) to the crest (the highest point) or to the trough (the lowest point).
- **Sketch:** If you were to sketch this, it would look like a wave where you draw a horizontal line in the middle (the rest position) and then show the distance from this line to the peak and the lowest point.

**Wavelength Measurement:**
- **Definition:** Wavelength is the distance between two consecutive points that are in phase on the wave, usually measured from crest to crest or trough to trough.
- **Measurement:** For the given wave from point X to point Y, you would measure the distance between two consecutive crests (or troughs) of the wave.
- **Provided Information:** In this case, you have indicated that the wavelength from X to Y is 4.8 meters.

### b) Wavelength in Metres

Since you have already provided the information that the wavelength from X to Y is **4.8 meters**, that is the answer.

### c) Wave Speed and Frequency

**Wave Speed Calculation:**
- To find the speed of the wave, we can use the formula:
\[
\text{Speed} = \frac{\text{Distance}}{\text{Time}}
\]
- The distance in one wavelength is 4.8 m, and the time taken from point X to point Y is 6.0 s. Therefore,
\[
\text{Speed} = \frac{4.8 \, \text{m}}{6.0 \, \text{s}} = 0.8 \, \text{m/s}
\]

**Frequency Calculation:**
- The frequency can be calculated using the relation between speed, frequency, and wavelength:
\[
\text{Speed} = \text{Frequency} \times \text{Wavelength}
\]
- Rearranging gives:
\[
\text{Frequency} = \frac{\text{Speed}}{\text{Wavelength}} = \frac{0.8 \, \text{m/s}}{4.8 \, \text{m}} \approx 0.167 \, \text{Hz}
\]

### d) Speed and Wavelength at 2.0 Hz Frequency

**New Wave Speed Calculation:**
- If the frequency of the source changed to **2.0 Hz**, we can find the speed using the wavelength which remains the same as we are interested in the effects of changing frequency:
- Using the previously given wavelength (4.8 m),
\[
\text{Speed} = \text{Frequency} \times \text{Wavelength} = 2.0 \, \text{Hz} \times 4.8 \, \text{m} = 9.6 \, \text{m/s}
\]

**New Wavelength Calculation:**
- The relation between speed, frequency, and wavelength can be rearranged as:
\[
\text{Wavelength} = \frac{\text{Speed}}{\text{Frequency}} = \frac{9.6 \, \text{m/s}}{2.0 \, \text{Hz}} = 4.8 \, \text{m}
\]

Thus, the wavelength remains **4.8 m**, even with the change in frequency.

### Summary:
- Amplitude and wavelength can be measured based on specific wave features.
- The wave speed with the initial conditions is 0.8 m/s, and frequency is approximately 0.167 Hz.
- At a frequency of 2.0 Hz, the speed would be 9.6 m/s, while the wavelength stays the same at 4.8 m.

anonymous anonymous answered
1 month ago

b) Find the wavelength in metres.

there are 3 crest waves and 3 trough waves. find 1 full wavelength

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
1 month ago

To find one full wavelength in a wave pattern that includes multiple crests and troughs, let’s clarify how we define a wavelength:

### Definition of Wavelength
A full wavelength is the distance between two consecutive points that are in phase. You can measure the wavelength as the distance from one crest to the next crest or from one trough to the next trough.

### Given Information
You mentioned that there are **3 crest waves and 3 trough waves** within the observed section of the wave.

### Visualizing the Wave
Let's visualize this:
- If there are **3 crests and 3 troughs**, the wave is likely completing **3 full wavelengths** in that section.

### Calculation of Wavelength
1. **If** you know the total distance that those 3 wavelengths span, you can find one wavelength by dividing that total distance by the number of wavelengths.

2. **Total Distance:** As stated earlier, the total distance from point X to point Y is **4.8 meters**.
3. **Number of Wavelengths:** Since we have **3 full wavelengths** within this distance, we can express the relationship mathematically:

\[
\text{Total Distance} = \text{Wavelength} \times \text{Number of Wavelengths}
\]

\[
4.8 \, \text{m} = \text{Wavelength} \times 3
\]

4. **Finding One Wavelength:**

\[
\text{Wavelength} = \frac{4.8 \, \text{m}}{3} = 1.6 \, \text{m}
\]

### Conclusion
Thus, each full wavelength is **1.6 meters**.