The diagrams show the displacement–distance graph for a wave and the displacement–time graph for a point in the wave - AQA - A-Level Physics - Question 17 - 2021 - Paper 1

The wavelength is the distance between two successive peaks of the wave in the displacement–distance graph. By measuring the distance from one wave peak to the next, it is evident that the distance is 6 m. Thus, this statement is correct.

To find the wave speed, we use the formula: $v = f \times \lambda$ where $v$ is the speed, $f$ is the frequency, and $\lambda$ is the wavelength. Given the frequency from the displacement–time graph is 0.17 Hz and the wavelength is 6 m, we calculate: $v = 0.17 \text{ Hz} \times 6 \text{ m} = 1.02 \text{ m/s}$. This indicates that this statement is incorrect.

The frequency is determined from the displacement–time graph by observing how many cycles occur in a given time period. The graphs indicate a frequency of 0.17 Hz, making this statement correct.