# Does mass affect friction?

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Definitely the answer to this question is afirmative. According to Newton's third law, the surface on which is supported a body of mass (m), acts on the body with a normal force (N); the value of this force is equal to the weight (mg) of the body and opposite.

N = m*g

Normal force (N) = body weight (mg)

For its part, the friction force is defined as the product of the normal force (N) by the coefficient of friction (μ) between the two surfaces:

Ff = μ*N = μ(m*g)

The friction coefficient depends only on the surfaces which are in contact and gravity has a constant value; therefore according to this expression; for a body at rest or moving on a surface, the frictional force is directly proportional to the mass (m) of the body.