A block placed on a rough adjustable incline just begins to slide down when the angle is

PHYSICS · Single correct · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics

Problem

2\,\text{kg}

block placed on a rough adjustable incline just begins to slide down when the angle is

20^{\circ}

. The plane is then fixed at

25^{\circ}

. A force of

12\,\text{N}

applied parallel and up the plane makes the block move upward with constant speed. Take

g = 10\,\text{m\,s}^{-2}

. Which pair of values is closest to the coefficients of static and kinetic friction

(\mu_s,\,\mu_k)

for the two cases? (a)

(0.46 ,\; 0.20)

(b)

(0.36 ,\; 0.20)

(c)

(0.36 ,\; 0.36)

(d)

(0.20 ,\; 0.36)