Circular motion in vertical plane

[Fu-Kwun Hwang]

A small sphere of mass m is attached to the end of a cord of length R, which rotates under the influence of the gravitation force in a vertical circle about a fixed point.
This applet shows how the speed of the sphere and the tension of the cord change.-*-

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.circularv_pkg.circularvApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_circularv.jar' name='circularv813' id='circularv813' width='300' height='342' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=813' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

[lookang]

Hi Prof,
actually this applet simulate a rod instead of a string.
i check the codes, it does not model projectile motion if the tension is insufficient to provide the centripetal acceleration.
is my understanding correct?

is would be cool if u could also release a string version! 

[Fu-Kwun Hwang]

Do you mean you want to simulate the case when the velocity is not large enough so the the particle become projectile motion?

[lookang]

A small sphere of mass m is attached to the end of a cord of length R, which rotates under the influence of the gravitation force in a vertical circle about a fixed point.
This applet shows how the speed of the sphere and the tension of the cord change.-*-

Yes, a cord/string version would be a good addition to your collection of simulation.

and the words in the top post should be rod instead of cord, because T can be negative to become support force on the mass m.
if cord=string then model would change to projectile motion when T - m*g*cos(theta) < m*v^2/r imply T = 0 and the motion is under gravity field only.

the difference is subtle but some sg school teacher use this example to trick the students during level test.

[Fu-Kwun Hwang]

I did created a simulation similar to what you have described.
However, it is only available in Chinese version. 雲霄飛車的物理:

I will create a new EJS version and post it here.

[lookang]

nice!
but i need an Ejs version to work on.
i doubt i can make one with different evolution equations
np
i try to learn from http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=448.0
and http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1803.0
thanks!
the location is Chicago,Illinois,United States, i am at Portland Oregon USA now

[Fu-Kwun Hwang]

Are you in the U.S. for AAPT meeting now?

I just created a quick verison of what you might need.

You can drag the gray dot to different height.
The string mode is what you want.

The following applet can be used to illustrate
1. conservation of energy
2. Collision between two particles. (two partialces are the same mass in the current version. I will add options for different mass later).
3. Pendulum or circular motion in vertical plane.

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.potentialenergycircularmotion_pkg.potentialenergycircularmotionApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_potentialenergycircularmotion.jar' name='potentialenergycircularmotion6894' id='potentialenergycircularmotion6894' width='897' height='484' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=6894' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

[lookang]

Are you in the U.S. for AAPT meeting now?

yes, it is from 17-21 july, here earlier to buy stuff and enjoy the trip.

I just created a quick version of what you might need.

You can drag the gray dot to different height.
The string mode is what you want.

The following applet can be used to illustrate
1. conservation of energy
2. Collision between two particles. (two particles are the same mass in the current version. I will add options for different mass later).
3. Pendulum or circular motion in vertical plane.

it is awesome man! i will look at code soon

[Fu-Kwun Hwang]

There were somw bugs. Please download updated version.

[lookang]

will work on it!
the code is simply great for learning.
thanks!

U should also start a new topic as well for the google search engine to tag your fantastic applet.
or i could do for u?

[Fu-Kwun Hwang]

You can post your modified version to a new topic.
Add collision with different mass might be too complicated for students.
I decided to keep the applet for the case of equal mass only.
It is similar to the Chinese version (single object sliding down the hill and turn into circular motion).

[ahmedelshfie]

Are you in the U.S. for AAPT meeting now?

Is this AAPT meeting i find on internet by google search  http://www.aapt.org/Conferences/sm2010/upload/Program-Book-7-7-10.pdf

[lookang]

yes!
page 91
FI05:  2:40–2:50 p.m.  Physics Educators as Designers of 
  Simulation Using Easy Java Simulation
Loo Kang WEE, Ministry of Education Singapore, MOE Building, 1 North
Buona Vista Dr. (S)138675, Singapore, 519935; weelookang@gmail.com
To deepen the professional practice of physics educators, we seek to high-
light the Open Source Physics (OSP) and Easy Java Simulation (Ejs) com-
munity of educators that engage, enable and empower teachers as learners
so that we can be leaders in our teaching practice. We learned through
Web 2 online collaborative means to develop simulations together with
reputable physicists through the open source digital library. By examining
the open source codes of the simulation through the Ejs toolkit, we are able
to examine and make sense of the physics from the computational models
created by practicing physicists. We will share some of the simulations that
we have remixed from existing library of simulations models into suitable
learning environments for inquiry of physics. 
http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0

[Fu-Kwun Hwang]

Great! I hope you have nice trip there and I believe you will learn a lot during the meeting.  Enjoy it! :-)

[lookang]

http://sgeducation.blogspot.com/2010/07/physics-educators-as-designers-of.html




Enjoy! Spreading the word for Open Source Physics and NTNUJAVA Virtual Physics Laboratory.
This professional learning community (PLC) in physics is simply awesome!

[Fu-Kwun Hwang]

It is really a wonderful talk. Thanks to the modern technology, I can watch/listen to your talk from Taiwan. 

[ahmedelshfie]

Great talk is really wonderful,, congratulation about this great meeting,, i watch/listen to you talk like prof Hwang but from Brazil 

[thejual]

great idea  http://www.thejual.com/