Question

friction graphs
15 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 static friction (μs) of these surfaces? type your answer..

Explanation:

Step1: Find the maximum static - friction force

From the graph, the maximum static - friction force ($F_{s,max}$) occurs at the point where the friction force stops increasing with the applied force. By observing the graph, $F_{s,max}=70\ N$.

Step2: Calculate the normal force

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

Step3: Use the formula for static - friction

The formula for the maximum static - friction force is $F_{s,max}=\mu_sN$. We can solve for the coefficient of static friction $\mu_s$ by rearranging the formula: $\mu_s=\frac{F_{s,max}}{N}$.
Substitute $F_{s,max}=70\ N$ and $N = 176.4\ N$ into the formula: $\mu_s=\frac{70}{176.4}\approx0.397$.

Answer:

$0.40$ (rounded to two decimal places)