for the following 2 examples from: http://www.physicsclassroom.com/class/energy/Lesson-1/Calculating-the-Amount-of-Work-Done-by-Forces A 10-N force is applied to push a block across a frictional surface at constant speed for a displacement of 5.0 m to the right. Would it be more accurate to say that a 10-N force is applied to 'Maintain' (not to push or pull) a block across a frictional surface at constant speed for a displacement of 5.0m to the right? because the 10-N force is acting upon the frictional force canceling it out in order for the block to continue moving at its original velocity. the 10-N force isn't acting on the block to push it when it is canceled out by friction. the block is in equilibrium with constant velocity. also An approximately 2-kg object is pulled upward at constant speed by a 20-N force for a vertical displacement of 5 m. Would it be more accurate to say that an approximately 2-kg object is 'moving' upward at a constant speed 'maintained' by a 20-N force for a vertical displacement of 5 m? because again, the tension force is acting not on the object but on the force of gravity. (any excess would be acting on the object). if a force is canceled out, it can't act on the object!! thanks.