Question

How long does it take for a secondary wave to travel 2,000 km

Answer 1

About 7 min.

Step-by-step explanation:

Secondary waves travel at speeds between 1 km/s and 8 km/s.

Let’s split the difference and assume that the wave travel at 4.5 km/s. Then

`\text{Time} = \text{2000 km} * \frac{\text{1 s}}{\text{4.5 km}} = \text{440 s }= \textbf{7.4 min}`