John is traveling north at 20 meters/second and his friend Betty is traveling south at 20 meters/second. If north is the positive direction, what are John and Betty's speeds? A.
-20 meters/second, 20 meters/second
B.
20 meters/second, -20 meters/second
C.
-20 meters/second, -20 meters/second
D.
0 meters/second, 40 meters/second

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).

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this