Monday, February 1, 2010

Why don't people fall off in the loops of a roller coaster?

(There are a few places where the text doesnt last too long, I was unable to fix it. So it is recomended you pause it when there is a lot being said.)
List of links I used to gather information: Roller Coaster by Gamer77

Like it? Create your own at It's free and fun!


  1. Very nice animation! There are however some misconceptions I found in this presentation. First, gravitational force pulls on a person, not pushes, and it does so at a force of 9.8 multiplied by the mass of the person not 9.8 m/s^2. 9.8 m/s^2 would be the acceleration of the person when only gravity is acting upon it. The part explaining the centripetal force could also be a little bit clearer. You said in your presentation that centripetal force pushes the person against the seat, but in reality centripetal force is always directed towards the center. So in the roller coaster case, the roller coaster is trying to fly off in a tangential line but the centripetal force (which is equal to the normal force in this case) is keeping it in a circular motion. I hope that clears things up a little bit for you.
    - Adrian

  2. Please explain what the objective of the project is.
    I agree with Adrian that there are some misconceptions in your explanations. For one thing, you seem to imply that the Centripetal Force is a special kind of force. That is not the case and you need to clarify it.
    Your digital tool should be embedded in your blog not just linked.

  3. I really liked your animated video! but the words moved just a little too fast because I had trouble reading the words in time before they changed. Also, the centripetal force is not a special kind of force, it is provided by the force that keeps the object moving in a circle. Also, you said that the normal force is equal to the normal force, what do you mean by that? You should clarify that. What forces are the centripetal force requirement? It is not very clear.

  4. This dialogue is a cool way of explaining physics! However, as the others have said, there are a few concepts that have to be explained more clearly. 9.8 m/s^2 is not the 'force' that is exerted by the earth on the person, but is the acceleration. When you explained that the normal force is equal to the normal force, did you mean gravitational force instead? For centripetal force, the force is always directed towards the center of the circle or, in this case, the loop. Also, in the comment from Adrian, he says that "the roller coaster is trying to fly off in a tangential line", that's due to Newton's First Law of Motion, which is inertia. The seat creates the centripetal force directed into the center to prevent the person from flying off. I hope this helps!

  5. The video is enbeded and linked. If you are unable to see it there might be a problem with your internet broswer and it might require a plugin. And for the dialect, I was unable to make it last longer so I shall seperate some of the things so you are able to read them. I shall also correctthe errors I have made. Thank you all for pointing out my mistakes.

  6. Your posting has to include a question, please check the project guidelines:
    1. Write a question related to the application.
    2. Clearly answer the question using a Digital Tool
    3. Document your sources: information and images.

  7. Your video makes a lot more sense now! The only things that needs fixing now is your explanation of inertia. I think you understand the concept, but the way you wrote it makes it sound like an object in motion stay at rest, which does not really work. Also, you're missing a 'to' when the guy asks 'what does centripetal force do'. Other than that, well done!

  8. I agree with the previous comment,please fix.

  9. Dear Daniel,

    That was an awesome animation - I actually enjoyed the fast pace, at least it wasn't slow and boring. It seems as though you fixed most of your conceptual errors, good job on that.

    Also, is that a string quartet cover of The Killers I hear?! Excellent choice!

    Keep on keeping on,
    Ben Caffrey from Arkansas