* Coefficient of friction (μ): This is a property of the materials in contact, not the object itself. It represents the ratio of the force needed to overcome friction to the normal force pressing the surfaces together.
* Force of friction (Ff): This is directly proportional to the normal force (Fn) and the coefficient of friction (μ): Ff = μ * Fn.
* Normal force (Fn): This is the force exerted by the surface perpendicular to the object. For a body resting on a horizontal surface, the normal force equals the object's weight (mass * acceleration due to gravity).
In summary:
1. Doubling the mass will double the normal force.
2. However, the coefficient of friction (μ) remains the same.
3. Therefore, the force of friction will also double, but the coefficient of friction itself will not change.
Example:
Imagine a block with a mass of 1 kg resting on a surface with a coefficient of friction of 0.2. The force of friction would be:
Ff = μ * Fn = 0.2 * (1 kg * 9.8 m/s²) = 1.96 N
If you double the mass to 2 kg, the force of friction would be:
Ff = μ * Fn = 0.2 * (2 kg * 9.8 m/s²) = 3.92 N
The force of friction doubles, but the coefficient of friction (0.2) stays the same.
