A Flatbed Truck Is Carrying a 20-Kg Crate Up a Sloping

Multiple Choice

A flatbed truck is carrying a 20-kg crate up a sloping road.The coefficient of static friction between the crate and the bed is 0.40,and the coefficient of kinetic friction is 0.30.What is the maximum angle of slope that the truck can climb at constant speed if the crate is to stay in place?

A) 0.38°
B) 13°
C) 17°
D) 22°
E) 68°