Answer:
μk = 0.08
Explanation:
- Applying the work-energy theorem, we know that the change in kinetic energy of the box, is equal to the total work done on it.
- The only force acting on the box capable of doing work, is the dynamic friction force.
- This force is just the product of the coefficient of kinetic friction, and the normal force.
- In this case, if the floor is level, the normal force is equal and opposite to the gravity force, Fg.
- So we can write the following expression:
[tex]\Delta K = -\frac{1}{2} * m* v_{0} ^{2} = \mu_{k} *m*g* cos (180\º)[/tex]
- Replacing by the givens, we can solve for μk, as follows:
[tex]\mu_{k} = \frac{v_{0}^{2} }{2*g*d} = \frac{9 (m/s)2}{2*9.8 m/s2*5.50m} = 0.08[/tex]
