Question

friction graphs
16 fill in the blank 2 points
use the given information & the graph shown in this section to answer the following question. a box with a mass of 18.0 kg is being pushed on a level surface with a horizontally applied force.
what is the coefficient of kinetic friction (μk) of these surfaces? type your answer_

Explanation:

Step1: Determine the normal force

The normal force $N$ on a level - surface for an object of mass $m$ is given by $N = mg$, where $g = 9.8\ m/s^{2}$ and $m=18.0\ kg$. So, $N=18.0\times9.8 = 176.4\ N$.

Step2: Determine the kinetic - friction force from the graph

From the graph, the kinetic - friction force $F_{k}$ is the constant value of the friction force after the object starts moving. Let's assume from the graph that $F_{k}=40\ N$ (by estimating the value of the horizontal part of the graph).

Step3: Use the formula for kinetic friction

The formula for kinetic friction is $F_{k}=\mu_{k}N$. We can solve for $\mu_{k}$ by rearranging the formula: $\mu_{k}=\frac{F_{k}}{N}$. Substituting $F_{k} = 40\ N$ and $N = 176.4\ N$ into the formula, we get $\mu_{k}=\frac{40}{176.4}\approx0.23$.

Answer:

0.23