Problem 7: Crates A and B have equal mass. Crate A is at rest on an incline that makes and angle of θ = 31.1 degrees to horizontal, while crate B is at rest on a horizontal surface. Part (a) Write an expression for the ratio of the normal forces, A to B, in terms of θ. Part (b) What is the ratio of the normal forces, A to B? NA/NB =