National League for Nursing (NLN) Science Practice Exam

A wave moves through its medium at 20 m/s with a wavelength of 4 m. What is the frequency of the wave?

1. 24 s−1

2. 5 s−1

3. 16 s−1

4. 80 s−1

The correct answer is: 5 s−1

To determine the frequency of a wave, you can use the relationship between wave speed (v), wavelength (λ), and frequency (f), which is expressed by the equation: \[ v = f \times λ \] In this particular scenario, the wave speed is given as 20 m/s, and the wavelength is 4 m. To find the frequency, you can rearrange the equation to solve for frequency: \[ f = \frac{v}{λ} \] Substituting the known values into the equation: \[ f = \frac{20 \text{ m/s}}{4 \text{ m}} \] Calculating this gives: \[ f = 5 \text{ s}^{-1} \] This calculation shows that the frequency of the wave is 5 Hz, which means the correct answer is indeed 5 s⁻¹. The frequency indicates how many wave cycles pass a point in one second, and in this case, it's 5 cycles per second.