A seismograph records a seismic wave that travels at 6 km/s. If the wave takes 30 seconds to reach the seismograph from the epicentre, how far is the epicentre from the seismograph? Provide the calculation.

Step-by-step solution

1. Use the basic speed‑distance–time relation: distance = velocity × time.
2. Insert the given velocity of 6 km/s and time of 30 s.
3. Multiply: $6\times 30=180$ km.
4. State that the epicentre is therefore 180 km away from the seismograph.

Concept tested: Seismic wave speed calculation

Published 7 October 2026 · How this solution was prepared and checked