Construct a travel time curve for the following data for both the forward and reverse profiles. Evaluate slopes and intercept times, and use those values to determine the subsurface structure for the first 2 layers, and then estimate the properties of the bottom layer. Offsets are in meters and times are in milliseconds.

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up