Answer
(a) The acceleration of the disk is $-0.853~m/s^2$
(b) The coefficient of kinetic friction is $0.087$
Work Step by Step
(a) We can find the acceleration:
$v_f^2 = v_0^2+2ad$
$a = \frac{v_f^2 - v_0^2}{2d}$
$a = \frac{0 - (3.2~m/s)^2}{(2)(6.0~m)}$
$a = -0.853~m/s^2$
The acceleration of the disk is $-0.853~m/s^2$
(b) We can use the magnitude of the acceleration to find the coefficient of kinetic friction:
$mg~\mu_k = ma$
$\mu_k = \frac{a}{g}$
$\mu_k = \frac{0.853~m/s^2}{9.80~m/s^2}$
$\mu_k = 0.087$
The coefficient of kinetic friction is $0.087$
