Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. neglecting air resistance, two seconds later the rock's speed is a. 15 m/s. b. 5 m/s. c. 10 m/s. d. zero. e. none of the above

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.