Answer:
The kinetic friction coefficient is 0.436
Step-by-step explanation:
In the attached image we can find a sketch of the forces that are acting over the box. And using the second law of movement of Newton we can find two equations which give us the relation between the friction force and the normal force.
The third equation is deducted by the definition of the friction force:
![f=u*N\\where\\u=kinetic friction coefficient\\N =normal force [N]\\](https://img.qammunity.org/2020/formulas/physics/middle-school/bou66cac3vszu2inn5uhyc2ezcvz51ikwz.png)
Then replacing the equation 1 (see image) in the equation 2 we will have the final equation. Then we can clear the value of u (kinetic coeficcient).
The answer is 0.436 and this value is between 0 - 1.