Problem 6-7 Friction coefficient - Part 2

A hockey puck travels \(33\; m\) along an ice rink before coming to rest. Its initial speed was \(11\;m/s\).

(a) What is the magnitude of the acceleration of the puck?
(b) What is the coefficient of kinetic friction between the puck and the ice?

Accumulated Solution

Diagram of puck with speed and direction indicated.

\(v_x{^2} = v_{0x}{^2} + 2a_xx \\ a_x = -1.83\; m/s^2 \; \text{ (answer to (a))}\)

\(v_x{^2}  = v_{0x}{^2} + 2a_xx \\ 0^2 = 11^2 + 2a_x(33) \\ a_x  = -1.83\; m/s^2\)

The minus sign means:

(A)   \(\text{The object is slowing down.}\)

(B)   \(\text{The object is speeding up.}\)

(C)   \(\text{You can't have a negative acceleration.}\)