Question

question 3 of 10 a sled of mass 8 kg slides across the ground with a friction force of 16.46 n. what is $mu_{k}$ between the sled and the ground? a. 2.1 b. 0.21 c. 0.49 d. 0.83

Explanation:

Step1: Calculate the normal force

The normal force $N$ on a horizontal surface for an object of mass $m$ is given by $N = mg$, where $g = 9.8\ m/s^{2}$ and $m = 8\ kg$. So $N=8\times9.8 = 78.4\ N$.

Step2: Use the friction - force formula

The formula for the kinetic - friction force is $F_f=\mu_kN$. We know $F_f = 16.46\ N$ and $N = 78.4\ N$. Rearranging for $\mu_k$, we get $\mu_k=\frac{F_f}{N}$. Substituting the values, $\mu_k=\frac{16.46}{78.4}\approx0.21$.

Answer:

B. 0.21