Block of mass rests on a rough plane inclined at to the horizontal

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

Problem

Block

A

of mass

4\,\text{kg}

rests on a rough plane inclined at

30^{\circ}

to the horizontal. It is connected by a light inextensible string over a smooth pulley to a hanging block

B

of mass

3\,\text{kg}

. The coefficient of kinetic friction between block

A

and the plane is

0.15

. When the system is released from rest, what is the magnitude and direction of the acceleration of block

B

? (a)

3.7\,\text{m\,s}^{-2}

downward (b)

0.7\,\text{m\,s}^{-2}

downward (c)

2.1\,\text{m\,s}^{-2}

downward (d)

0.7\,\text{m\,s}^{-2}

upward