In a shuffleboard game, the puck slides a total of 12 m on a horizontal surface before coming to rest. If the coefficient of kinetic friction between the puck and board is 0.10, what was the initial
Speed of the puck?
A) 3.8 m/s
B) 48.5 m/s
C) 4.8 m/s
D) 4.3 m/s

Question

Quizplus · Accepted Answer

The initial speed of the puck can be found using the work-energy principle. The work done by friction is equal to the change in kinetic energy. The work done by friction is $W = f_k \cdot d = \mu_k \cdot m \cdot g \cdot d$, where $f_k$ is the force of kinetic friction, $\mu_k$ is the coefficient of kinetic friction, $m$ is the mass of the puck, $g$ is the acceleration due to gravity (9.8 m/s$^2$), and $d$ is the distance (12 m). The change in kinetic energy is $\Delta KE = \frac{1}{2} m v^2 - 0$, since the puck comes to rest. Setting the work done by friction equal to the change in kinetic energy and solving for $v$ (initial speed), we don't need the mass of the puck as it cancels out. Using the given coefficient of kinetic friction (0.10) and the distance (12 m), we can solve for $v$. The calculation simplifies to $v = \sqrt{2 \cdot \mu_k \cdot g \cdot d}$, which gives $v = \sqrt{2 \cdot 0.10 \cdot 9.8 \cdot 12} \approx 4.8$ m/s.

In a Shuffleboard Game, the Puck Slides a Total of 12