A person(A) is trying to keep his balance while on a sled(B) that is sliding down an icy incline. the weight of A and B are Wa=181lbs, Wb=50 lbs. Determine the minuimum coeffeicent of static friction between A and B required for A not to slide with respect to B if θ = 23. Friction between the sled and the incline is negligible.