1. The problem statement, all variables and given/known data The object is a box with a given mass m. Our person has the choice between pushing the box with a horizontal force, or pulling the box with a wire with an angle of θ=30o. The magnitude of Fo is the force vector he affects the box with in both cases. Should the box be pushed or pulled in order to achieve the greatest acceleration? 2. Relevant equations I've made a drawing of each situation adding all the forces acting on the box. Situation 1 http://myupload.dk/handleupload/c5fd9W9J18EBn Situation 2 http://myupload.dk/handleupload/4a037-RJ3a5Ha 3. The attempt at a solution I've been trying to write an equation describing the net-force in both situations. I've here made the assumption that in both cases n and Fg cancels each other out. For situation 1 I get: Fnet=Fo-ff I know that there's some sort of friction acting in the opposite direction and that it's given by ff=[itex]\mu[/itex]n For the force vector Fo I can apply newton's 2nd law for the x composant, since the box is not changing direction in the y-axis. Therefor I get: Fnet=max0-μn For situation 2 I get: Fnet=Fo*sin(θ)-μn The force vector must be dependent on the magnitude from the forces acting in the direction of x and y. By applying newton's 2nd law again I get: Fnet=mao*sin(θ)-μn Judging situation 1, by pushing with a horizontal force, the acceleration will be constant. However in situation 2, different angles of pulling will result in different accelerations. I believe that he will then achieve the greatest acceleration by pushing it. This to me is a difficult one to figure out so I would like some help on what I did wrong, it's important to me to learn.