Equation for solving the coefficient of Kinetic friction HELP?

[susyq232]

Equation for solving the coefficient of Kinetic friction HELP??

Problem: A cable attached to a block of mass 9 kg pulls the block along a horizontal floor at a constant velocity. If the tension in the cable is 5.2 N, what is the coefficient of kinetic friction between the block and the floor?




Questions:I have tried to solve this but i really don't know where to begin.
Whats the equation to calculate the coefficient of Kinetic Friction?


Attempt: ok i know Mass= Friction/Gravity and gravity is 9.8,
u=friction(k)/Normal force


Fg= 9kg* (9.8)= 88.2 kg

Ef=Ma = 5.2n +Ffk= 9kg * o m/s^2 = Ffk=-5.2 n

[uk]= 5.2/100 = 0.052 m/s^2

is this right? so confused


i really just don't have any idea about the the equation...HELP??

 

[Kurdt]

If the block is moving at a constant speed then there must be no net force on the block. That is the friction cancels out the force pulling it. Take a look at the following page about friction and have another go.

http://hyperphysics.phy-astr.gsu.edu/hbase/frict2.html