Suppose a ray of light traveling in a material with an index of refraction na reaches an interface with a material having an index of refraction nb. Which of the following statements must be true for total internal reflection to occur? a. The angle of incidence must be less than the critical angle.
b. The angle of incidence must be equal to the critical angle.
c. The angle of incidence must be greater than the critical angle.

Which situation will produce the greatest change of momentum

Which best describes what forms in nuclear fission? a. two smaller, more stable nucleib. two larger, less stable nucleic. one smaller, less stable nucleusd. one larger, more stable nucleus

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.