Physics

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