A block moves along a straight frictionless track in

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

Problem

A block moves

3\,\text{m}

along a straight frictionless track in

5\,\text{s}

. The force acting on it is

10\,\text{N}

over the first

2\,\text{m}

and

20\,\text{N}

over the next

1\,\text{m}

, both along the direction of motion. What is the average power delivered to the block during this

5\,\text{s}

interval? (a)

12\,\text{W}

(b)

8\,\text{W}

(c)

6\,\text{W}

(d)

9\,\text{W}