Final answer:
True, passing on an uphill grade without clear visibility is unsafe. The concept is relevant to health and physical education as it relates to the increases in potential energy and effort leading to exhaustion when cycling uphill, and the conversion of energy and heat dissipation when coasting over hills.
Step-by-step explanation:
True, it is generally unsafe to pass on an uphill grade if you do not have a clear view of the path ahead. While this question may initially seem like a driving safety concern, it is closely related to physical fitness and health education, particularly in the context of outdoor activities such as cycling. When tackling an uphill path, whether on a bike or in a vehicle, the potential for dangers increases due to the reduced visibility and the additional challenges presented by the incline. As for the potential and kinetic energy aspects of the question, when a cyclist moves uphill, they indeed increase their potential energy due to gaining height against gravity. This requires more effort, which can lead to exhaustion if the cyclist tries to maintain the same speed they had on flat ground, thus attempting to keep their kinetic energy high. Furthermore, when coasting downhill and then back uphill to a lower point, it's true that not all of the potential energy will convert back into kinetic energy; some will dissipate as heat through friction, for example, warming up the bicycle tires.