Answer
$6.0 \times 10^3$ J.
Work Step by Step
The lawn’s area is 200 square meters, and the lawnmower’s width is 0.5 m. That means that the mower must be pushed a distance of (200/0.5) = 400 meters.
The force and the displacement are both forward. The angle between them is 0 degrees. Use equation 6–1.
$$W=(15 N)(400 m)(cos 0^{\circ}) = 6.0 \times 10^3 J$$
