1. what is the velocity of a p - wave if it travels 99 kilometers in 12 seconds? (give your answer in km/s)…
1. what is the velocity of a p - wave if it travels 99 kilometers in 12 seconds? (give your answer in km/s) 4 points km/s 2. if an earthquake started in columbia, mo, how long (time) will it take for a wave traveling at 2.3 km/s to reach salina? salina is 481 km from columbia, mo. your answer 3. the epicenter of an earthquake is 200 km away. if p - waves from this earthquake travel at a velocity of 6.1 km/s, how long before you feel the thud of the first p - wave? your answer 4. an earthquake was recorded in san diego. the seismograph record shows that the p - waves first arrived at 10:02 and the s - waves first arrived at 10:03. what is the lag time for this earthquake? 2 points
Answer
Explanation:
Step1: Recall velocity formula
Velocity $v=\frac{d}{t}$, where $d$ is distance and $t$ is time.
Step2: Calculate velocity for question 1
Given $d = 99$ km and $t=12$ s, then $v=\frac{99}{12}=8.25$ km/s.
Step3: Recall time - distance - velocity relation for question 2
$t=\frac{d}{v}$, with $d = 481$ km and $v = 2.3$ km/s. So $t=\frac{481}{2.3}=209.13$ s.
Step4: Calculate time for question 3
Using $t=\frac{d}{v}$, with $d = 200$ km and $v=6.1$ km/s. Then $t=\frac{200}{6.1}\approx32.79$ s.
Step5: Calculate lag - time for question 4
The lag - time is the time difference between the arrival of s - waves and p - waves. 10:03 - 10:02=1 minute = 60 s.
Answer:
- 8.25 km/s
- 209.13 s
- 32.79 s
- 60 s