An object with a mass of #8 kg# is on a plane with an incline of # - pi/12 #. If it takes #12 N# to start pushing the object down the plane and #9 N# to keep pushing it, what are the coefficients of static and kinetic friction?

1 Answer
May 14, 2017

I assume that the angle of inclination is #pi/12# instead provided ,
we know for that

enter image source here

from the FBD diagram we can conclude that

#f_("static")=mgmucostheta#

#f_("dynamic")=mgmusintheta#

substituting the values you can get your answer (here a in the image is the angle you provided)

#mu_("static")=f_("static")/(mgcostheta)#

#mu_("dynamic")=f_("dynamic")/(mgsintheta)#