To calculate the wavelength of a radio wave, we use the formula: \(\lambda = \frac{v}{f}\) where: - \( v \) is the speed of the wave, - \( f \) is the frequency. Given: - Frequency \( f = 400 \, \text{kHz} = 400 \times 10^3 \, \text{Hz} \) - Speed \( v = 3.0 \times 10^{-8} \, \text{m/s} \) Substituting the values into the formula: \(\lambda = \frac{3.0 \times 10^{-8} \, \text{m/s}}{400 \times 10^3 \, \text{Hz}}\) Calculating: \(\lambda = \frac{3.0 \times 10^{-8}}{4.0 \times 10^5}\) \(\lambda = 7.5 \times 10^{-14} \, \text{m}\) Thus, the wavelength of the radio wave is: \(\lambda = 7.5 \times 10^{-14} \, \text{m}\)