Three people pull simultaneously on a stubborn donkey. jack pulls directly ahead of the donkey with a force of 63.9 n63.9 n , jill pulls with 79.1 n79.1 n in a direction 45° to the left, and jane pulls in a direction 45° to the right with 183 n183 n . (since the donkey is involved with such uncoordinated people, who can blame it for being stubborn? ) find the magnitude of the net force the people exert on the donkey.

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.