Question

What equation gives the magnitude of kinetic friction?

a) ( f_k = mu_k times N )

b) ( f_k = N )

c) ( f_k = mu_s times N )

d) ( f_k = mu_k times m )

Answer 1

The equation that gives the magnitude of kinetic friction is represented by
`f k​ =μ k​ ⋅N`.Thus the option c) ( f_k = mu_s times N ) is correct.

Step-by-step explanation:

The equation for kinetic friction is expressed as
`f k​ =μ k​ ⋅N`, where
`f k` is the magnitude of kinetic friction, μk is the coefficient of kinetic friction, and N is the normal force. This equation indicates that the force of kinetic friction is directly proportional to the normal force and depends on the surface characteristics, as denoted by the coefficient of kinetic friction.

In the given options, (c) correctly represents the equation for kinetic friction. The coefficient μk is a dimensionless constant that characterizes the surface interaction between two objects in motion relative to each other.

The normal force (N) is the perpendicular force exerted by a surface to support the weight of an object resting on it. Therefore, the correct equation
`f k​ =μ k​ ⋅N` emphasizes that the magnitude of kinetic friction is determined by the product of the coefficient of kinetic friction and the normal force.

In conclusion, option (c) provides the accurate equation for kinetic friction, highlighting the role of both the coefficient of kinetic friction and the normal force in determining the magnitude of the frictional force between two surfaces in relative motion.

Thus the option c) ( f_k = mu_s times N ) is correct.