An object with a mass of #12 kg# is on a plane with an incline of # - pi/6 #. If it takes #6 N# to start pushing the object down the plane and #3 N# to keep pushing it, what are the coefficients of static and kinetic friction?

1 Answer

Coefficient of Static Friction #mu_s=0.05891329277#
Coefficient of Kinetic Friction #mu_k=0.02945664639#

Explanation:

The given data:

#theta=(-pi)/6=-30^@#
mass #m=12" "#kg

Force needed to move the object down #F_s=6" "#N
Force needed to continue moving the object down #F_k=3" "#N

Compute the normal force #F_n#

#F_n=m*g*cos (pi/6)=12*(9.8)*cos (pi/6)=101.8445875" "#N

Compute for the Coefficient of Static Friction #mu_s#

#F_s=mu_s*F_n#
#6=mu_s(101.8445875)#

#mu_s=6/101.8445875#
#mu_s=0.05891329277#

Compute for the Coefficient of Kinetic Friction #mu_k#

#F_k=mu_k*F_n#
#3=mu_k(101.8445875)#

#mu_k=3/101.8445875#

#mu_k=0.02945664639#

God bless....I hope the explanation is useful.