Answer:
The distance between the beginning of the first P wave and the first S wave tells you how many seconds the waves are apart.
Step-by-step explanation:
This number will be used to tell you how far your seismograph (an instrument that measures and records details of earthquakes, such as force and duration) is from the epicenter (the point on the earth's surface vertically above the focus of an earthquake) of the earthquake. Measure the distance between the first P wave and the first S wave.