Physics

Problem

An explosion occurs inside a straight mine shaft that is

680\,\text{m}

long. A seismograph on the ground records the vibration that travels through the surrounding rock at

5100\,\text{m/s}

, while a microphone at the shaft opening records the sound that travels through the air inside the shaft at

340\,\text{m/s}

. Approximately how much later does the microphone signal arrive compared to the seismograph reading? a)

0.14\,\text{s}

2.13\,\text{s}

1.9\,\text{s}

2.0\,\text{s}