During a hockey game, a puck is given an initial speed of 10 m/s. It slides 50 m on the horizontal ice before it stops due to friction. What is the coefficient of kinetic friction between the puck and
The ice?
A) 0.090
B) 0.11
C) 0.12
D) 0.10

Question

Quizplus · Accepted Answer

To find the coefficient of kinetic friction ($\mu_k$), we can use the work-energy principle. The work done by friction is equal to the change in kinetic energy. The formula for the work done by friction is $W = \mu_k F_n d$, where $F_n$ is the normal force, and $d$ is the distance. Since the puck is on a horizontal surface, $F_n = mg$, where $m$ is the mass of the puck and $g$ is the acceleration due to gravity. The change in kinetic energy ($\Delta KE$) is given by $\frac{1}{2}mv^2 - 0$, since the puck stops ($v = 0$).Setting the work done by friction equal to the change in kinetic energy gives us:$$\mu_k mgd = \frac{1}{2}mv^2$$Solving for $\mu_k$ gives:$$\mu_k = \frac{v^2}{2gd}$$Substituting $v = 10 \, m/s$, $g = 9.8 \, m/s^2$, and $d = 50 \, m$ gives:$$\mu_k = \frac{(10)^2}{2(9.8)(50)} = \frac{100}{980} = 0.102$$Rounded to two decimal places, the coefficient of kinetic friction is 0.10.

During a Hockey Game, a Puck Is Given an Initial