Final answer:
Hills are unsafe during thunderstorms because their height and isolation make them likely lightning targets. Golfers carrying metal clubs or those under trees are at risk due to increased height and tree's conductive nature. Cars provide some safety due to the Faraday cage effect, protecting the interior from lightning strikes.
Step-by-step explanation:
Places on hills are unsafe during thunderstorms because they are elevated and isolated, making them a more likely path for lightning to strike. Lightning tends to hit the tallest object in an area, and a hilltop provides that height advantage. Moreover, the presence of solitary trees or structures on hills further increases the risk as they can attract lightning.
In the case of a golfer carrying a metal club, this extends the height and offers a conductive path, highly increasing the vulnerability to a lightning strike. Sheltering under a tree is also unsafe because trees are natural lightning conductors. If hit, the lightning can jump to a nearby object, including a person seeking shelter.
For similar reasons, during electrical storms, driving a car offers some protection because the car's metal body can act as a Faraday cage, shielding the inside of the car from the effects of outside electrical fields. Thus, while inside a metal car, the impact of a lightning strike is dispersed over the exterior, and the interior remains safe, provided you do not touch metal parts.