A certain type of laser emits light that has a frequency of 5.6 x 1014 Hz. The light, however, occurs as a series of short pulses, each lasting for a time of 3.9 x 10-11 s. (a) How many wavelengths are there in one pulse? (b) The light enters a pool of water. The frequency of the light remains the same, but the speed of the light slows down to 2.3 x 108 m/s. How many wavelengths are there now in one pulse?