A laser beam of wavelength λ = 632. 8 nm shines at normal incidence on the reflective side of a compact disc. The tracks of tiny pits in which information is coded onto the cd are 1. 60 μm apart.

Afish fossil is found in a rock. a foot bone and tooth are found in an older layer of the same rock. what can scientists learn from the rock? a) the area changed from land to water. b) the area changed from water to land. c) the area has always been land. d) the area was once an ocean.