text: # Two cars X and Y
  
  Question:
  
  Two cars $\mathrm{X}$ and $\mathrm{Y}$ are approaching each other with velocities $36 \mathrm{~km} / \mathrm{h}$ and $72 \mathrm{~km} / \mathrm{h}$ respectively. The frequency of a whistle sound as emitted by a passenger in car X, heard by the passenger in car $\mathrm{Y}$ is $1320 \mathrm{~Hz}$. If the velocity of sound in air is $340 \mathrm{~m} / \mathrm{s}$, the actual frequency of the whistle sound produced is ........ Hz.
  
  Solution:
  
  $\mathrm{V}_{\mathrm{x}}=36 \mathrm{~km} / \mathrm{hr}=10 \mathrm{~m} / \mathrm{s}$
  
  $\mathrm{V}_{\mathrm{y}}=72 \mathrm{~km} / \mathrm{hr}=20 \mathrm{~m} / \mathrm{s}$
  
  by doppler's effect
  
  $\mathrm{F}^{\prime}=\mathrm{F}_{0}\left(\frac{\mathrm{V} \pm \mathrm{V}_{0}}{\mathrm{~V} \pm \mathrm{V}_{\mathrm{s}}}\right)$
  
  $1320=\mathrm{F}_{0}\left(\frac{340+20}{340-10}\right) \Rightarrow \mathrm{F}_{0}=1210 \mathrm{~Hz}$
explanation: The document contains a physics problem involving the Doppler effect. It presents a question about the actual frequency of a whistle sound produced by a passenger in one car as heard by a passenger in another car, and it also provides a detailed solution to the problem.
distilabel_metadata.content: Evaluate the user given text extract and determine if it contains a math question and optionally and answer to this question.
  
  Output rules:
  
  1. Briefly describe the document and mention if it contains a question or a question and answer.
  2. Finalize the output with: Label: no-question,question,question-and-answer,multiple-question,multiple-question-and-answer
distilabel_metadata.role: system
distilabel_metadata.content: # Two cars X and Y
  
  Question:
  
  Two cars $\mathrm{X}$ and $\mathrm{Y}$ are approaching each other with velocities $36 \mathrm{~km} / \mathrm{h}$ and $72 \mathrm{~km} / \mathrm{h}$ respectively. The frequency of a whistle sound as emitted by a passenger in car X, heard by the passenger in car $\mathrm{Y}$ is $1320 \mathrm{~Hz}$. If the velocity of sound in air is $340 \mathrm{~m} / \mathrm{s}$, the actual frequency of the whistle sound produced is ........ Hz.
  
  Solution:
  
  $\mathrm{V}_{\mathrm{x}}=36 \mathrm{~km} / \mathrm{hr}=10 \mathrm{~m} / \mathrm{s}$
  
  $\mathrm{V}_{\mathrm{y}}=72 \mathrm{~km} / \mathrm{hr}=20 \mathrm{~m} / \mathrm{s}$
  
  by doppler's effect
  
  $\mathrm{F}^{\prime}=\mathrm{F}_{0}\left(\frac{\mathrm{V} \pm \mathrm{V}_{0}}{\mathrm{~V} \pm \mathrm{V}_{\mathrm{s}}}\right)$
  
  $1320=\mathrm{F}_{0}\left(\frac{340+20}{340-10}\right) \Rightarrow \mathrm{F}_{0}=1210 \mathrm{~Hz}$
distilabel_metadata.role: user
distilabel_metadata.raw_output_q_a_detector_0: The document contains a physics problem involving the Doppler effect. It presents a question about the actual frequency of a whistle sound produced by a passenger in one car as heard by a passenger in another car, and it also provides a detailed solution to the problem.
  
  Label: question-and-answer