National League for Nursing (NLN) Science Practice Exam

What is the frequency of a wave traveling at a speed of 20 m/s with a wavelength of 2 m?

1. 10 s−1

2. 20 s−1

3. 30 s−1

4. 40 s−1

The correct answer is: 10 s−1

To determine the frequency of a wave, you can use the wave equation, which relates wave speed, frequency, and wavelength. The equation is: \[ \text{Speed} = \text{Frequency} \times \text{Wavelength} \] In this case, the speed of the wave is given as 20 m/s, and the wavelength is 2 m. Rearranging the equation to solve for frequency gives us: \[ \text{Frequency} = \frac{\text{Speed}}{\text{Wavelength}} \] Substituting the values you have: \[ \text{Frequency} = \frac{20 \, \text{m/s}}{2 \, \text{m}} = 10 \, \text{s}^{-1} \] Therefore, the frequency of the wave is indeed 10 s⁻¹, which matches the first choice. This calculation clearly shows how the wave's speed and wavelength lead to the determination of its frequency.