A block sits against a vertical wall and a 120 lb force P acts diagonally to the left on the block at an angle below the horizontal. Determine the magnitude and direction of the friction force which the vertical wall exerts on the 100 lb block if theta is (a)15 degrees (b)30 degrees

For part a I got that the answer is 46.36 lb up but I can't get part b to work correctly.

2 answers

You have provided incomplete information.

Were you given a value for the coefficient of friction? From what direction is theta measured?
yeah the coefficient of static friction is 0.5 and coeffient of kinetic friction is 0.4. theta is measured below the horizontal