Final answer:
The safety of bicyclists on the road versus the sidewalk depends on various factors; however, roads may be safer due to visibility and predictability for vehicle drivers. Cyclists convert potential energy to kinetic energy when climbing hills, which can be exhausting, and a bicycle helmet is an important safety measure.
Step-by-step explanation:
The statement 'Bicyclists are safer on the road than on the sidewalk' is true or false can depend on various factors such as traffic laws, cyclist expertise, and specific road and sidewalk conditions. Generally, cyclists on sidewalks may have more conflicts with pedestrians and are less visible to vehicles crossing intersections, leading to increased accident risks. However, on the road, cyclists are more visible and predictable to motorists, although they must contend with moving traffic.
In reference to statement 11, it is true that a cyclist coasting down one hill and up another will stop at a point lower than where they started. This is because some of the potential energy is indeed converted to heat due to friction, warming the tires, and thus not all energy is available to climb the second hill to the same height.
Regarding statement 35, it is false that riding a bicycle up a gentle hill easily increases your kinetic energy. It increases your potential energy, and doing so can make a cyclist feel exhausted due to the physical effort required.
In the scenario described in statement 38, from the bicyclist's frame of reference, you are moving to the left as the bicyclist is passing by toward your right.
It is important for cyclists to make healthy choices, like wearing a bicycle helmet to protect from head injuries and respect other trail users and the environment, as bicycle tires can cause less trail damage compared to horses' hooves and maintain peaceful coexistence on trails.