Question

when drawing a free - body diagram for an object on an inclined surface, which way does the normal force point?
a. parallel to the surface
b. straight down
c. straight up
d. perpendicular to the surface

Explanation:

The normal force is a contact force that acts perpendicular to the surface. For an object on an inclined surface, by definition, the normal force is perpendicular to the inclined - surface.

• Option A: Parallel to the surface is incorrect as the normal force is not parallel.
• Option B: Straight down is the direction of the gravitational force (weight component in some cases), not the normal force.
• Option C: Straight up would be the case for a horizontal surface, but for an inclined surface, it's not straight up.
• Option D: Perpendicular to the surface is correct as per the definition of the normal force.

Answer:

D. Perpendicular to the surface