Question

question 1 / 4
the graph shown represents the applied forces on an object. the first part of
the graph represents the ______ friction.
click image to enlarge graph.

a. applied force
b. kinetic friction
c. normal force
d. static friction

Explanation:

To solve this, we recall the concepts of friction: Static friction opposes the initiation of motion and increases with the applied force until the object starts moving (after which kinetic friction acts, which is generally constant). The first part of a force - friction graph (where friction increases with applied force) corresponds to static friction. Kinetic friction is constant once motion starts, applied force is what's being applied (not friction in the sense of opposing motion here), and normal force is related to the force perpendicular to the surface (not directly shown in this part of the force - friction graph for opposing motion). So the first part of the graph representing the friction (that increases with applied force before motion) is static friction.

Answer:

D. static friction