Question

what is the relationship between friction and force? *
friction increases as the applied force increases.
friction decreases as the applied force increases.
friction is not affected by force.
friction only depends on the color of the surfaces.

Explanation:

Friction is a force that opposes motion. When an applied force acts on an object, static friction initially matches the applied force (up to a maximum value). Kinetic friction is relatively constant but still related to the normal force (which can be influenced by applied forces in some cases). As the applied force increases (before motion), static friction increases to counter it. Even for kinetic friction, in some scenarios (like if the applied force affects the normal force, e.g., pushing an object against a wall), friction (normal force × coefficient) can be affected. The other options are incorrect: friction doesn't decrease as applied force (relevant to its opposition) increases in the typical sense of opposition; it is affected by force (as explained); and color of surfaces has no relation to friction (friction depends on surface roughness, normal force, etc.).

Answer:

Friction increases as the applied force increases.