A hockey puck moving at 7.00 m/s coasts to a halt in 80.0 m on a smooth ice surface.What is the coefficient of friction between the ice and the puck?
A)μ = 0.109
B)μ = 0.031
C)μ = 0.063
D)μ = 0.094
E)μ = 0.156

Question

A hockey puck moving at 7.00 m/s coasts to a halt in 80.0 m on a smooth ice surface.What is the coefficient of friction between the ice and the puck?
A)μ = 0.109
B)μ = 0.031
C)μ = 0.063
D)μ = 0.094
E)​μ = 0.156

Quizplus · Accepted Answer

The initial velocity (u) of the puck is 7.00 m/s, the final velocity (v) is 0 m/s, the distance (s) traveled is 80.0 m, and the acceleration (a) is calculated using the formula v^2 = u^2 + 2as.
Therefore, a = - (u^2) / 2s = - (7.00^2) / 2(80.0) = -3.06 m/s^2 (negative because the puck is decelerating).
The coefficient of friction (μ) between the ice and the puck can be calculated using the formula a = μg, where g is the acceleration due to gravity (9.81 m/s^2).
Thus, μ = a/g = -3.06/9.81 = -0.312, but since the coefficient of friction cannot be negative, we take the absolute value.
μ = 0.312.
The closest choice is B (μ = 0.031).

A Hockey Puck Moving at 7