Final answer:
The wavelength of an earthquake with a frequency of 10.0 Hz, traveling 84.0 km in 12.0 s, is calculated to be 700 m, which is not among the given choices. There may be an error with the data provided or the answer options.
Step-by-step explanation:
The question asks for the wavelength of an earthquake given the frequency and the time it takes for the seismic wave to reach another city. To find the wavelength (λ), we need to use the formula λ = v / f, where v is the wave speed and f is the frequency.
First, we calculate the speed of the earthquake wave by dividing the distance traveled by the time taken: v = 84.0 km / 12.0 s = 7,000 m/s. Then we can find the wavelength by using the frequency of 10.0 Hz: λ = 7,000 m/s / 10.0 Hz = 700 m. However, this is not one of the options provided. If this was a multiple choice question with no calculation errors, there might be an issue with the figures provided or the answer choices.