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Grade 12th passWave Motion

Find the ratio of intensity of wavetrain A and B. also find frequency in both graphs?

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Profile image of Parul Rajput
9 Years agoGrade 12th pass
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ApprovedApproved Tutor Answer1 Year ago

To determine the ratio of intensity between wavetrain A and wavetrain B, as well as their respective frequencies, we need to analyze the characteristics of each wavetrain. Intensity in wave mechanics is often related to the amplitude of the wave, while frequency is determined by how many cycles occur in a given time period. Let's break this down step by step.

Understanding Intensity

Intensity (I) of a wave is proportional to the square of its amplitude (A). This relationship can be expressed mathematically as:

I ∝ A²

Thus, if we know the amplitudes of both wavetrains, we can find the ratio of their intensities using:

Ratio of Intensities (I_A/I_B) = (A_A²)/(A_B²)

Finding the Amplitudes

To find the amplitudes of wavetrains A and B, you would typically look at the peak values of the waves on their respective graphs. For example, if wavetrain A has a peak amplitude of 4 units and wavetrain B has a peak amplitude of 2 units, the calculation would be:

  • Amplitude of A (A_A) = 4
  • Amplitude of B (A_B) = 2

Substituting these values into our intensity ratio formula gives:

I_A/I_B = (4²)/(2²) = 16/4 = 4

This means the intensity of wavetrain A is four times greater than that of wavetrain B.

Determining Frequency

Frequency (f) is defined as the number of cycles per second, measured in Hertz (Hz). To find the frequency from a graph, you can look at the time period (T), which is the duration of one complete cycle. The relationship between frequency and time period is given by:

f = 1/T

Analyzing the Graphs

For each wavetrain, identify the time it takes to complete one full cycle. For instance, if wavetrain A completes a cycle in 0.5 seconds and wavetrain B completes a cycle in 1 second, the frequencies would be calculated as follows:

  • Frequency of A (f_A) = 1/0.5 = 2 Hz
  • Frequency of B (f_B) = 1/1 = 1 Hz

Thus, wavetrain A has a frequency of 2 Hz, while wavetrain B has a frequency of 1 Hz.

Summary of Findings

In summary, the ratio of intensity between wavetrain A and wavetrain B is 4:1, indicating that A is significantly more intense. The frequencies are 2 Hz for wavetrain A and 1 Hz for wavetrain B. This analysis not only helps in understanding the properties of the waves but also illustrates the fundamental relationships between amplitude, intensity, and frequency in wave mechanics.