Grade 11 Physics: WAVES. Finding Wavelength & Frequency

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To find the wavelength of a sound wave, use the formula velocity = frequency x wavelength. For the sound produced by middle C (256 Hz), with the speed of sound at 343 m/s, the wavelength can be calculated as approximately 1.34 meters. For high C (512 Hz), the wavelength is about 0.671 meters. In the second question, the frequency of the child's swinging is correctly calculated as 0.4 Hz, and the period can be found using the formula period = 1/frequency, resulting in 2.5 seconds. Understanding these formulas is essential for solving wave-related physics problems.
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I missed the day where we were taught the formulas for frequency & wavelength, so doing the questions below are a struggle. Please someone explain how .


Question 1 (wavelength) : The speed of sound in air at room temperature is 343m/s. The sound wave produced by striking middle C on a piano has a frequency of 256 Hz.
A) Calculate the wavelength of this sound
B) Calculate the wavelength for the sound produced by high C, one octave higher than middle C, with a frequency of 512 Hz.
^ This one I had no idea how to even start. :$

Question 2 (frequency) : A child swings back and forth on a swing 12 times in 30.0 seconds. Determine the frequency and period of the swinging.
^ This one I did the answer as f/t = 12/30 = .4 so is 0.4 Hz correct?
 
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Question one: you know that velocity of the wave=frequency*Wavelength...that should help you get the wavelength I think.
Question two: I think you did that right..dont forget you also need to calculate the period for that. Remember period=1/frequency
 

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