An object slides on a level floor. It slows and comes to a stop with a constant acceleration of magnitude 2.4 m/s². What is the coefficient of kinetic friction between the object and the floor?
A) 0.24
B) 0.12
C) 0.48
D) It is impossible to determine without knowing the mass of the object.

Question

Quizplus · Accepted Answer

The coefficient of kinetic friction is given by the equation:$$f_k = \mu_k * n$$where:* $f_k$ is the force of kinetic friction* $\mu_k$ is the coefficient of kinetic friction* $n$ is the normal forceIn this problem, the normal force is equal to the weight of the object:$$n = mg$$where:* $m$ is the mass of the object* $g$ is the acceleration due to gravityThe force of kinetic friction is equal to the mass of the object times the acceleration:$$f_k = ma$$where:* $a$ is the acceleration of the objectSubstituting these equations into the first equation, we get:$$\mu_k = \frac{ma}{mg} = \frac{a}{g}$$Plugging in the given values, we get:$$\mu_k = \frac{2.4 \ m/s^2}{9.8 \ m/s^2} = 0.24$$Therefore, the coefficient of kinetic friction is 0.24.

An Object Slides on a Level Floor