Final answer:
The illusion of being pulled uphill on a magnetic hill is due to visual cues misinterpreted by the brain, similar to the feeling of altered weight in a fast-moving elevator. Real forces, such as gravity and normal force, explain these sensations through Newton's laws of motion. In non-inertial frames, fictitious forces like the centrifugal force are perceived, which result from the frame's acceleration.
Step-by-step explanation:
The phenomenon of feeling like being pulled uphill on a magnetic hill when actually coasting downhill is a type of optical illusion that occurs due to the surrounding landscape. These illusions happen because of the way our brains interpret the visual clues in our environment, causing a mismatch between perception and reality. In the case of a magnetic hill, the horizon may be obscured or the slope of the road relative to the surroundings might be misjudged, leading us to think we're being pulled uphill.
Similar effects occur in different contexts, as Einstein illustrated with the example of an elevator. When an elevator accelerates rapidly either upwards or downwards, passengers experience a change in weight due to acceleration, which could be measured by a scale. This change in weight is due to the net force acting on a person, altering the normal force and hence the apparent weight. Similarly, on an amusement park ride where riders are pinned to the wall of a rotating barrel, it's not a fictitious force but the centripetal force necessary for circular motion that causes this sensation.
This can be related to the centrifugal force, which is another fictitious force experienced in a rotating frame of reference like a rapidly spinning merry-go-round. In these non-inertial frames of reference, such forces are used to explain the sensation of being thrown outward, while the real forces can be understood in terms of Newton's laws in an inertial frame of reference like the Earth's. In the example of the roller coaster, gravity is the real force doing work, translating potential energy into kinetic energy during the ride.