The force of kinetic friction between two surfaces is independent of the area of contact between the surfaces.Group of answer choicesTrueFalse

Answer to the Question

The statement "The force of kinetic friction between two surfaces is independent of the area of contact between the surfaces" is True.

Explanation

1. Understanding Kinetic Friction: Kinetic friction is the force that opposes the motion of two surfaces sliding past each other. It is characterized by a coefficient of kinetic friction ($\mu_k$) which depends on the two materials in contact.

2. Friction Force Formula: The force of kinetic friction ($F_k$) can be calculated using the formula: $F_k = \mu_k \cdot N$ where $N$ is the normal force (the force perpendicular to the two surfaces).

3. Independence from Area: The critical point of this statement lies in the understanding that the frictional force depends primarily on the normal force and the coefficient of friction; not on the surface area in contact. As the area increases, the pressure (force per unit area) decreases proportionately, keeping the frictional force constant.

4. Conclusion: Therefore, the size of the contact area does not affect the total force of kinetic friction, making the statement true.

In summary, the assertion that the force of kinetic friction is independent of the area of contact is accurate and supported by the fundamental principles of frictional forces.