The Infusion at Blackpool Pleasure Beach in Blackpool, England -- a suspended looping coaster
Dave Thompson
Roller Coasters and Your Body
Your body feels acceleration in a funny way. When a coaster car is speeding up, the actual force acting on you is the seat pushing your body forward. But, because of your body's inertia, you feel a force in front of you, pushing you into the seat. You always feel the push of acceleration coming from the opposite direction of the actual force accelerating you.
This force (for simplicity's sake, we'll call it the acceleration force) feels exactly the same as the force of gravity that pulls you toward the Earth. In fact, acceleration forces are measured in g-forces, where 1 g is equal to the force of acceleration due to gravity near the Earth's surface (9.8 m/s2, or 32 ft/s2).
A roller coaster takes advantage of this similarity. It constantly changes its acceleration and its position to the ground, making the forces of gravity and acceleration interact in many interesting ways. When you plummet down a steep hill, gravity pulls you down while the acceleration force seems to be pulling you up. At a certain rate of acceleration, these opposite forces balance each other out, making you feel a sensation of weightlessness -- the same sensation a skydiver feels in free fall. If the coaster accelerates downward fast enough, the upward acceleration force exceeds the downward force of gravity, making you feel like you're being pulled upward. If you're accelerating up a steep hill, the acceleration force and gravity are pulling in roughly the same direction, making you feel much heavier than normal. If you were to sit on a scale during a roller coaster ride, you would see your "weight" change from point to point on the track.
At the top of a hill in a conventional coaster, inertia may carry you up, while the coaster car has already started to follow the track down. Let go of the safety bar, and you'll actually lift up out of your seat for an instant. Coaster enthusiasts refer to this moment of free fall as "air time."
Shandale McKay:
ReplyDeleteIt was interesting to see the ways gravity and acceleration work on rollercoasters. I never knew that the actual force you feel on a rollercoaster is the seat pushing up against you.
Tulsi Patel:
ReplyDeleteI have actually been on this ride before. It is pretty cool to read this and understand how it works.
I love roller coasters and I never thought about how the acceleration is always in the opposite direction of how you feel it and how the force is actually pushing against you.
ReplyDeleteVery interesting. The moment of weightlessness would explain why I almost felt like I was pulled out of my seat during the Splash Mountain ride at Disney world.
ReplyDeleteThis is really cool. I had no idea the feeling of weightlessness comes from opposite forces balancing out.
ReplyDeleteKelly Martens:
ReplyDeleteI always wanted to know what caused the feeling of weightlessness on roller coasters. I definitely want to go skydiving for the same feeling of weightlessness.
I love roller coasters and it was interesting to understand why I feel weightless at certain times on different roller coasters when I'm riding them. My understanding of my body's reactions to the positions of a roller coaster is also more clear.
ReplyDeleteThis makes me think of the Hulk ride at Islands of Adventure because in the begging they accelerate upward without KE conserved from gravity and you immediately feel like your trying to push through the seat.
ReplyDeleteKyle Green
KATIE KELLY:
ReplyDeleteI am not much of a roller coaster person and the fact that I would "lift out of my seat" pretty much makes me never want to even think about getting on another roller coaster!! Also, when going down a steep hill, you say that the force of gravity is pulling you down and the acceleration force is pulling upward on you...is this why it feels like your stomach drops????
I'm assuming that the larger the value of the g forces during the ride the heavier you feel and the greater the force of the seat pushing on you? I love roller coasters and have always questioned the physics of the ride itself. To me, it seems that i feel heavier and a greater amount of force being applied when going up an incline to go upside down rather than coming down after a loop. Based on your information given I am going to assume then that the gforces are greater accelerating up and incline than down.
ReplyDeletenever thought about roller coasters in this way, regarding the "weightlessness"... very interesting
ReplyDeleteI never thought about the force you feel on a roller coaster coming from the seat and not the air. That is interesting.
ReplyDeleteLori Waite
I have always love roller coasters, specifically the feeling of the wind rushing past my face and through my hair. I never really thought about the fact that the seat is pushing me, causing an opposite force, with the exception of The Hulk at Islands of Adventure that thrusts one through a tunnel at the beginning.
ReplyDeleteRoller coasters provide the weirdest sensations. G-force is hard to explain to someone who has never felt it. Thanks for the article
ReplyDeleteThe gravity and acceleration interaction in rollercoasters is what makes them so much fun.Although I never knew that the force is coming from the seat.So the bodies inertia is what makes us believe the force is in front of us, very interesting.
ReplyDeleteKelsey Irvine:
ReplyDeleteI agree with Katie. I don't like roller coasters at all. All those strange feelings are exactly why I avoid them. That kind of physics just scares me.
This is definitely counter intuitive. Great post.
ReplyDeleteJessica Lang