A block slides along a horizontal track while a horizontal force acts on it as it moves

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

Problem

A block slides along a horizontal track while a horizontal force acts on it as it moves. From

x=0\,\text{m}

x=2\,\text{m}

the force is

+5\,\text{N}

(directed in the

+x

direction). From

x=2\,\text{m}

x=4\,\text{m}

the force decreases uniformly to

0\,\text{N}

. From

x=4\,\text{m}

x=6\,\text{m}

the force is

-3\,\text{N}

(directed opposite the motion). During which interval is the work done by the force on the block negative? (a)

2\text{ m} \le x \le 4\text{ m}

(b)

4\text{ m} \le x \le 6\text{ m}

(c)

0\text{ m} \le x \le 6\text{ m}

(d)

2\text{ m} \le x \le 6\text{ m}