A block is held against a vertical wall by a constant horizontal force of

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

4\,\text{kg}

block is held against a vertical wall by a constant horizontal force of

100\,\text{N}

. The coefficients of friction between the block and the wall are

\mu_s = 0.5

and

\mu_k = 0.3

. The block is given a brief downward push so that it starts sliding downward. The magnitude of its acceleration during the slide is (a)

9.8\,\text{m/s}^2

downward (b)

2.3\,\text{m/s}^2

downward (c)

0.94\,\text{m/s}^2

downward (d)

2.7\,\text{m/s}^2

upward