Question:medium

What is the frequency of a wave with a speed of \(30\,m/s\) if the distance between 11 consecutive crests is \(1\,m\)?

Show Hint

If \(n\) consecutive crests are given, the number of wavelengths between them is \(n-1\). Use this to determine the wavelength before applying \(v = f\lambda\).
Updated On: May 13, 2026
  • \(30\,Hz\)
  • \(300\,Hz\)
  • \(330\,Hz\)
  • \(3\,Hz\)
Show Solution

The Correct Option is B

Solution and Explanation

Topic - Physics: Wave Motion
Step 1: Understanding the Question:
Given the wave speed and the total distance covering a specific number of crests, we need to calculate the frequency of the wave.
Step 2: Key Formula or Approach:
1. Wave velocity formula: \(v = f\lambda\)

2. Wavelength (\(\lambda\)): The distance between two consecutive crests.

3. For \(n\) consecutive crests, there are \((n - 1)\) wavelengths.
Step 3: Detailed Solution:
Given distance = \(1\,m\) for 11 consecutive crests.
Number of wavelengths (\(n-1\)) = \(11 - 1 = 10\).
\[ 10\lambda = 1\,m \]
\[ \lambda = \frac{1}{10} = 0.1\,m \]
Given speed \(v = 30\,m/s\).
Using \(v = f\lambda\):
\[ f = \frac{v}{\lambda} = \frac{30}{0.1} = 300\,Hz \]
Step 4: Final Answer:
The frequency of the wave is \(300\,Hz\).
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