What is the smallest value of the force F such that the 8.0 kg block will not slide down the wall? The coefficient of static friction between the block and the wall is 0.4. Select one:
a. 10N
b. 100N
c. 200N
d. 98N

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.