Is there a case where #N#, normal force = #f#, frictional force?? When a nail is hit into an object?

1 Answer
Aug 8, 2017

The equation relating the friction force and the coefficient of kinetic friction is

#ulbar(|stackrel(" ")(" "f_k = mu_kn" ")|)#

where

  • #f_k# is the magnitude of the kinetic friction force, the force that acts when the object is in motion, and in the direction opposite to the motion

  • #mu_k# is the coefficient of kinetic friction

  • #n# is the magnitude of the normal force exerted by the surface the object is on

From a mathematical approach, if the friction force #f_k# equals the normal force #n#, then

#f_k = (1)n#

The coefficient of kinetic friction is then equal to #1#.

So we're basically asking for situations where the coefficient of kinetic friction of the two interacting materials is equal to #1#.

According to this web site, there a few materials where the static friction coefficient is equal to #1#, but no values of #1# are listed for the kinetic friction coefficient. That doesn't mean it's not possible, it simply means it hasn't been documented on that site.

Maybe you could find one yourself!