When does total internal reflection occur?

a. when the angle of incidence exceeds the angle of reflection

b. when the angle of incidence is less than the angle of reflection

c. when the angle of incidence is less than the critical angle

d. when the angle of incidence exceeds the critical angle

give a strait answer

Aboat travels at 15 m/s in a direction 45° east of north. the boat then turns and travels at 18 m/s in a direction 5° north of east. what is the magnitude of the boat's resultant velocity? round your answer to the nearest whole number. /s what is the direction of the boat's resultant velocity? round your answer to the nearest whole degree. ° north of east