Assume a crust 35 km thick with a P wave velocity of 6.1 km/sec, overlying a mantle with P wave velocity of 8 km/sec. For an earthquake with hypocenter at 20 km depth: 1) What is the time of arrival of the reflection from the Moho at the surface if you are standing at the epicenter? 2) At a distant station, what would be the time difference between direct P and the reflected phase (pP) ? Assume near vertical incidence angle near the source. 3) What is the distance (horizontally from the epicenter) where the head wave starts to show up on seismic stations? 4) What is the time of arrival of the P wave that reflects off the mantle at the same place on the surface (from Q3 ) where the head wave starts to appear?