Solutions
KM#10: Layers of the Earth (Level 3)
Mathematical Content: Basic algebra (distance, rate and time); geometry; Snell’s law
PROBLEM 1: Using the known travel time and distance, compute the velocity of the seismic wave.
Distance d = 80km, time t = 12.3 seconds
PROBLEM 2: Find the distance this second wave traveled. (Use the information about the second wave and the velocity you have computed.)
Rate = 6.5km/s, time t = 18.8 seconds
Distance 
PROBLEM 3: Can you guess what path that this second wave traveled?
See picture.
PROBLEM 4: Compute the depth SQ of the barrier. (Use the information together with your previous answers to compute SQ, the depth of the barrier).
Use Pythagorean Theorem:
PROBLEM 5: Compute the radius of the interior barrier.
