An object with a mass of #9 kg# is on a plane with an incline of # - pi/4 #. If it takes #24 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
Jun 11, 2017

Answer:

Static friction coefficient=1.4

Kinetic friction coefficient=0.144

Explanation:

m=9kg;#theta#=45°;g=#9.8ms^-1#
In 1st case,
#mu#mg#costheta#=24+mg#sintheta#
#=>(mu-1)/sqrt2=(24×sqrt2)/(9×9.8)#
#=>mu=1.4#
In 2nd case,
#mu#mg#costheta#=9
#=>mu=(9×sqrt2)/(9×9.8)#
#=>mu=0.144#