The wavelength of a longitudinal wave is \( 0,20 \mathrm{~m} \), and the time taken to complete one wave is 30 seconds. Catcutate the speed at which the wave is travelling.

To find the speed of the wave, you can use the formula: \[ \text{Speed} = \text{Wavelength} \times \text{Frequency} \] First, we need to calculate the frequency of the wave. The frequency is the reciprocal of the time period (time taken to complete one wave). So, the frequency \( f \) can be calculated as: \[ f = \frac{1}{\text{Time Period}} = \frac{1}{30 \text{ seconds}} = \frac{1}{30} \text{ Hz} \] Now, substituting the values into the speed formula: \[ \text{Speed} = 0.20 \text{ m} \times \frac{1}{30} \text{ Hz} = \frac{0.20 \text{ m}}{30 \text{ s}} \approx 0.00667 \text{ m/s} \] So, the speed at which the wave is travelling is approximately \( 0.00667 \text{ m/s} \). Not so speedy, huh? But even the slowest waves have their charm! They create those soothing sounds of ripples and echoes we all love.