1. The problem statement, all variables and given/known data A block rests on a wedge inclined at angle [tex] \theta [/tex]. The coefficient of friction is [tex] \mu [/tex]. The wedge is then given a horizontal acceleration a. Assuming that [tex] \tan (\theta) < \mu [/tex], find the minimum acceleration for the block to remain on the wedge without sliding. 2. Relevant equations 3. The attempt at a solution I've been working angles like crazy and can't even get the theory down, much less come up with the equation. The block would slide off the wedge if not given an acceleration, and once the min. acceleration to keep the block on the wedge is reached the force of friction changes direction and will now be pointed down the wedge if acceleration increases. I don't want a worked solution, only some help explaining the forces at work in this problem.