Circular Motion Videos by CB Tung

Go to this link and watch the video about the physics of amusement parks.

nwsphysics99 — 2015-02-25 20:04:22 UTC

http://www.pbslearningmedia.org/resource/phy03.sci.phys.mfw.roller/centripetal-force-roller-coaster-loops/

Then return here and comment specifically on something new you learned from the video.

If there Wasn't centripetal force then a person would keep going up in the loop. The centripetal force pushes down, allowing the roaersoaster to change direction.

2015-02-26 21:09:37 UTC

J-LEZ

Centripetal Force on Roller Coaster loop

2015-02-27 21:35:05 UTC

I learned that every time I sat on the roller coaster, not only the seat beats are keeping me from falling out, but also the centripetal force. The centripetal force in the loop are pushing the cart in every direction and changing its directions. Steven M.

Sarah

2015-03-01 22:38:36 UTC

I thought it was interesting that when building the

roller coaster, they have to make the track lower than the height you would reach if you, theoretically, were launched

off the tracks.

Brian Lowe

2015-03-01 22:48:15 UTC

I would like to learn more about

what other parts of physics are factors

in building roller coaster, such as why

certain designs wouldn't work.

Abbey S

2015-03-02 00:47:23 UTC

I knew before that physics were involved and considered when creating amusement park rides, but I did not know that the rides were created (in this case) in a way that even without a saftey restraint you would still be safe on the loop of the ride.

Charlotte

2015-03-02 01:25:01 UTC

I learned that that the "imaginary path"

(outlined in the pink) has to be much higher

than the actual loop and this is exactly what pulls you down again when your going around a loop.

Riley H

2015-03-02 06:12:30 UTC

I learned that to come out of a loop and not go flying (like with the board and the cup of water), you have to continue forward. You can't just stop.

I learned that the force pushes towards the center of the cirle.

2015-03-02 06:43:26 UTC

-Sophie K

Danny

2015-03-02 07:42:05 UTC

I found it was the normal force from the tracks providing the centripetal force for everyone on the roller coaster.

Still I would not dare to try it.

Carrie S

2015-03-02 14:19:10 UTC

I learned that the curve of the loop has to be smaller (more curved, less tall) that the curve you would follow due to gravity if you were launched off the roller coaster track.

Forrest Henry

2015-03-02 16:20:15 UTC

I learned that when a roller coaster goes through a loop, the loop pushes on you, and you are pushed on the loop.

Magic.

Seamus

2015-03-02 17:18:25 UTC

I learned that if the roller coaster, the seat belts, and the carts disappeared at the beginning of the curve, we would all probably die (due to the imaginary loop bringing us higher than the actual loop and then dropping us all the way down due to gravity).

Evan

2015-03-02 17:19:54 UTC

I learned that you can keep a glass of water from spilling

while turning it upside down if you apply enough centripital force

Andrew

2015-03-02 17:24:40 UTC

I observed, much like Cecilias toy, that when centripital

force is applied to an object even when turned at

any angle, it will sustain its original properties of rest,

simulated, like a glass of water, a bowl of jello, or even

a twisty roller coaster platform with fifty humans on it.

Julia

2015-03-02 18:22:53 UTC

I learned that there is more to keeping you glued to your

seat in a roller coaster loop than just your safety belt. The

centripetal force keeps you down, even though you are upside

down. Yay.

Graham

2015-03-02 18:24:31 UTC

Nothing really new here. It was interesting

how he stopped the swinging platform with

the water glass by increasing the radius of the

circle, decreasing centripetal force.

Adam

2015-03-02 18:30:22 UTC

It never really occurred to me that the force on the cup would be perpendicular to the wood base at all times. I had heard about the force keeping the water in the cup, but the level of the water stayed completely still the entire time.

Henry

2015-03-02 19:12:03 UTC

In my experience on roller coasters, I have noticed this. the video emphasized the idea that even though it is somewhat counter-intuitive, we are being held down by gravity. Of course, everyone has seen the classic spin the bucket full of water trick but I never really compared it to a roller coaster.

Sam Waller

2015-03-02 19:27:45 UTC

I learned that it is both the track and gravity which provide the centripetal force that push down on the car which pushes on you so that you stay in your seat.

Olivia

2015-03-03 00:57:51 UTC

I learned that centripetal force pushes into the center of the circle which allows for the car to continuosly move in a direction and push into the center of the circle from different points in the circle.

Sarah R

2015-03-03 02:15:35 UTC

I had never really thought about the physics of a roller coaster so I found this video very interesting. I learned that the track together with gravity provides the centripetal force needed to keep a roller coaster car turning and that it requires centripetal force pushing towards the center of the circle to continuously change the direction of the car. I was really amazed by the cup on board experiment and would love to test something like that out.

Samy

2015-03-03 04:34:27 UTC

I learned that it is centripetal force that is keeping me in my seat during a loop-de-loop. I also learned that David Wright is an awesome man.

Josefina

2015-03-03 17:11:46 UTC

I learned that it is both the car and the centripetal force of the looped roller coaster that keeps one in their seat when traveling upside down, since the centripetal force pushed to the center of the circle, and continuously changes the direction of the car. However this still does not want to make me go on a roller coaster that goes upside down.

Halley

2015-03-03 19:59:00 UTC

I thought it was interesting that the centripetal force caused the object being acted upon to continuously change direction, and that your centripetal force makes you want to go higher than the roller coaster will let you.

Tai

2015-03-03 20:14:19 UTC

I have never really thought that centripetal force plays a part in keeping us in our seats during roller coaster rides. I certainly recall feeling like I was pushed against the center of a loop when I was on a ride at Disney Land a few years back. The professor's ability to keep the cup of water from spilling at the stopping point was also extremely impressive.

Chloe Q

2015-03-03 20:14:59 UTC

I found it interesting that the centripetal force keeps us "sticking" to the roller coaster seat because I used to think that gravity is the only force which makes us dropping down.

Ty

2015-03-03 21:11:58 UTC

It was nothing that i didn't already know as far as a force keeping the items from falling. I'm glad that physics is on my side while i'm riding a roller coaster. it would be interesting to study some of the other physics of roller coasters.

Lucas

2015-03-03 21:37:14 UTC

I learned that without centripetal force, there would be no such thing as roller coaster loop-de-loops.

Vincent

2015-03-03 21:39:00 UTC

I thought that the cup on the board demonstration was impressive, because it showed the principles behind centripetal force in a low tech way. I also thought the way the teacher brought the cup to a stop was cool, because it was something you would do without thinking about it, but actually uses the principles of centripetal force by increasing the radius of the circle to slow it.

Maddie

2015-03-04 05:57:00 UTC

I learned that gravity AND centripetal force keep me in my roller coaster seat. The water cup demonstration (both in the video and the one Cecelia did in class) helped for me to understand this.