. A cross-country skier moves from location A to location B to location C to location D. Each leg of the backand-forth motion takes 1 minute to complete; the total time is 3 minutes. (The unit is meters.)

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).

b) phosphorus pentoxide