1. The problem statement, all variables and given/known data Anthony is going to drive a flat-bed truck up a hill that makes an angle of 10 degrees wtih respect to the horizontal direction. A 36.0-kg package sits in the back of the truck. The coefficient of static friction between the package and the truck bed is 0.380. What is the maximum acceleration the truck can have without the package falling off the back? 2. Relevant equations Force of friction<(=) mu of static friction(normal force) 3. The attempt at a solution So I drew a FBD. I found two forces in the horizontal: the force of friction and the force of the pull. And two vertical forces: the normal force and the force of gravity. I aligned the Normal force, the force of friction and the force of the pull with the axis, and then split the gravity into x and y components. 4. Confusion Am I correct on the horizontal force of pull? And would this be acceleration? If so, is it appropriate to say that the sum of forces equals the force of friction + the force of acceleration = ma? This is where I'm confused. I think that once I clear this up I can solve the problem. Thanks for any help!