Question

Explain why roads on hills are built to wind around in gentle slopes rather than going straight up (Fig.).

Answer 1

On a hill, a road functions like an inclined plane. The length L of a road with mild slopes is significantly more than the height h that needs to be climbed.

Mechanical advantage of an inclined plane = `L/h`

Longer roads with mild slopes have higher `L/h` values, which indicate that significantly less force (work) is needed to ascend the hill. Vehicles can climb more easily and safely because, while having to travel a greater distance, less force is required at any given time. The vehicle's engine might not be able to supply the enormous force needed to go straight up.