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On a Ferris wheel, your body feels different at different points of the ride. You feel lighter at the top of the wheel, and then heavier at the bottom. Why?
Let’s start by defining some forces that are involved in the process. According to Observation Wheel Directory, velocity is speed with a direction, and acceleration is the rate of velocity change over time. Gravity is the force that pulls an object toward the center of something, like the center of the Earth.
Because of the circular shape of a Ferris wheel, the acceleration in this case is called centripetal acceleration, and its direction is always toward the center of the circle.
Finally, normal force is the force that surfaces exert on objects to keep them from passing through them. If you sit on a chair, the chair is exerting normal force on you to keep you from falling right through it!
When you first get on the ride, your body feels normal because it has not accelerated yet.
Once the ride starts, you begin moving up and away from the ground until you are at the top of the Ferris wheel. At this point, your body feels “lighter” because the force of gravity and the normal force, of your seat, are working in opposite directions. The center of the ride is below you, so the centripetal acceleration is pulling you down, too.
As you travel around the center of the Ferris wheel, the force of gravity, normal force and centripetal force all are pushing and pulling against you.
As you approach the bottom of the ride, you feel “heavier” because the normal force of your seat has to increase, and the centripetal force is now pulling you up.
According to Real World Physics Problems, the only time you’ll feel your “normal” weight is on the sides, directly to the left or right of the center of the Ferris wheel, when the centripetal acceleration is pointing horizontally.
Of course, your weight never actually changes on this ride — just your perception of it.
Mishka MohamedNour is a junior at West High School and a reporter and a designer for the West Side Story.