A shear wave is propagating upward, at an angle of 30 degrees from vertical, through a bedrock layer that has a shear wave velocity of 3000 ft/s. When the wave reaches an overlying layer of soil with a shear wave velocity of 600 ft/s, a portion of the wave energy is transmitted (refracted) into the soil layer. (a) If the rock-to-soil interface is horizontal, at what inclination from vertical will the refracted shear wave be traveling just after it enters the soil layer? (b) If the shear wave in the bedrock is a frequency of 10 Hz, what will the shear wave length be in the soil layer?