Question

To practice Tactics Box 10.1 Calculating the work done by a constant force. To find the work done on an object by a force, begin with a visual overview and follow Tactics Box 10.1. Recall that the work W done by a constant force F⃗ at an angle θ to the displacement d⃗ is W=Fdcosθ. The vector magnitudes F and d are always positive, so the sign of W is determined entirely by the angle θ between the force and the displacement. What is the work Wn done on the box by the normal force?

Answer 1

No work id done by Fn. Even for a block sliding up or down an incline, the normal force does no work. The normal force by definition is petpendicular to the surface,; no component of the normal force is parallel to the motion. Consider a person standing in an elevator.