Final answer:
By taking the longer road, the force required to maintain a constant velocity of the stroller is halved due to a gentler slope, but the work done remains unchanged since the vertical height does not vary with road length.
C is correct
Step-by-step explanation:
When you push a stroller up a hill on two different roads where one is twice as long as the other, we can consider the force required to keep the stroller moving at a constant velocity and the work done represented by the product of force and distance (force times length of the road).
If you choose the longer road, the force required to push the stroller up at a constant velocity is less because the slope is more gradual. This means the force component along the slope of the longer road would be smaller. Since work is the product of force and displacement in the direction of the force, while the force decreases, the distance increases in such a way that the work (force times distance) remains the same as the shorter path. This is because the vertical height the stroller must be raised (which ultimately determines the gravitational work done) does not change with the length of the road.
The correct answer is therefore (C) halve the force required to keep the stroller moving at constant velocity, while leaving the product of that force times the length of the road unchanged.