What's the free body diagram for:
Mr. Seifert needs to push a cardboard box down the hallway for Ms. Wang. The box has a mass of 40 kg and he is pushing it with an acceleration of 2 m/s/s. Because the cardboard does not slide easily, there is a friction force of 25 Newtons acting on the box to the LEFT. How much force is Mr. Seifert applying to the box to move it forward to the RIGHT?
