If a 4 kg4kg object moving at 5/4 m/s54ms slows to a halt after moving 8 m8m, what is the coefficient of kinetic friction of the surface that the object was moving over?

1 Answer
Jun 26, 2016

~~0.010.01

Explanation:

Given
m->"Mass of the object"=4kgmMass of the object=4kg

m->"Velocity of the object"=5/4m/smVelocity of the object=54ms
g->"Acceleration due to gravity"=9.8m/s^2gAcceleration due to gravity=9.8ms2

d->"Distance travelled before halt"=8mdDistance travelled before halt=8m

mu_k->"Coefficient of kinetic friction"=?μkCoefficient of kinetic friction=?

Considering law of conservation of energy we can say,
"work done against friction =KE of the object"work done against friction =KE of the object

=>mu_kmgxxd=1/2*mv^2μkmg×d=12mv2

=>mu_k=v^2/(2*g*d)=(5/4)^2/(2*9 .8*8)~~0.01μk=v22gd=(54)229.880.01