Final answer:
The work done against the gravitational force when carrying a school bag on a leveled road is zero because the displacement is perpendicular to the force of gravity (cos(90°) = 0). The correct answer is option (d).
Step-by-step explanation:
The question concerns the work done against gravitational force when a girl is carrying a school bag on a level road. The work done by a force is given by the formula
work (W) = force (F) × distance (d) × cos(θ),
where θ is the angle between the force and the direction of motion.
Since the force of gravity acts vertically downward and the girl is moving horizontally, the angle between the gravitational force and the direction of motion is 90 degrees.
The cosine of 90 degrees is zero, therefore, the work done against gravitational force is zero because the displacement is perpendicular to the direction of gravity.