Final answer:
As the angle of elevation on an incline increases, the normal force acting on a block on that incline will decrease, regardless of the block's mass.
Step-by-step explanation:
When considering the effect of an increased angle of elevation on a block on an incline, it's important to understand that the force of gravity acting on the object is divided into two components: one acting perpendicular to the plane (w1) and the other acting parallel to the plane (wl). Consequently, as the angle of elevation increases, the normal force (N), which is equal and opposite to the perpendicular force of weight, will decrease. This is because the perpendicular component of the weight will decrease, while the parallel component increases, causing less force to act perpendicularly against the plane.
Therefore, the correct answer to the question of how the normal force acting on a block on an incline would change as the angle of elevation increases is: c. decrease. This change in normal force occurs irrespective of the mass of the block as it relates to the components of gravitational force on an inclined plane.