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Fu-Kwun Hwang
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« on: January 29, 2004, 01:24:44 PM » |
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Registed user can get files related to this applet for offline access.If java program did not show up, please download and install latest Java RUN TIMEor
When the two balls are launched from one end of the track with the same initial velocity, what will happen: 1) the ball #1 on the straight track arrives at the other end first
2) the ball #2 on the track with the dip arrives at the other end first
3) the race is a tie - both balls reach the other end at the same time?
This is a java version for one of our physics demostration. Think about it, select the answer to active the program.
Did you get the correct answer?
Press the start button to restart.
- Click the left button within the window will suspend the animation
click it again to resume. - Clcik the right mouse button and drag it up and down
to change the shape of the lower track.
- Click more information checkbox to display more information
- Shape of the track ( from left to right)
section 1 red curve: part of a circle (1/4)
tangential component of the gravitation field is the source of the acceleration.
section 2 blue curve: Trajectory for a projectile
(with initial velocity when it entering this region)
So, horizontal component of the velocity is a constant.
section 3 red curve: part of a circle.
The solpe for the curves match at the boundary.
particle will accelerate (as section 1) but with different acceleration
sectin 4 blue curve: Trajectory for projectile similar similar to section 2
section 5 green line: horizontal line.
The velocity is a constant in this region.
- The horizontal component of the velocities are also shown.
This applet was originated from one of the demonstrations developed by Prof. Berg (Dept. of physics at Maryland, College Park) many years ago. or
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Fu-Kwun Hwang
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« Reply #1 on: January 24, 2005, 03:47:46 PM » |
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Velocity of ball 2 >= velocity of ball 1 !
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Guest
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« Reply #2 on: June 17, 2004, 11:40:07 AM » |
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why (mechanical) energy conservation cannot be used?
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Guest
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« Reply #3 on: June 18, 2004, 11:06:44 AM » |
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Energy is conservation in the above situation. Could you explain more why you think energy conservation can not be used?
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Guest
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« Reply #4 on: August 20, 2004, 09:47:50 PM » |
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Because of Friction I think... (need source code of this program  ) |
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spoung45
Newbie
Posts: 1
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« Reply #5 on: October 19, 2004, 12:06:01 PM » |
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Well its becuse of the acceleration of the ball down in the second dip that gives it more velocity. saying there is no friction involved ball 2 gains more velocity after the second dip.
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Fu-Kwun Hwang
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« Reply #6 on: October 20, 2004, 07:07:15 AM » |
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Please click the image to see the real demonstration (mpg)  |
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Fu-Kwun Hwang
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« Reply #7 on: January 26, 2005, 10:58:07 AM » |
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Let Vx is the horizontal component of the velocity
Vx2 >= Vx1 so ball 2 has longer horizontal displacement than ball 1.
The above condition is true if the slope is not too large so that ball 2 is always stay on track.
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Fu-Kwun Hwang
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« Reply #8 on: February 12, 2005, 01:54:33 PM » |
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Horizontal velocity of ball 2 is either the same or greater than Horizontal velocity of ball 1 during the who trip.
So the horizontal displacement of ball 2 is larger than the horizontal displacement of ball 1. :-)
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rattapong
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« Reply #9 on: October 13, 2007, 05:38:54 PM » |
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Horizontal velocity of ball 2 is either the same or greater than Horizontal velocity of ball 1 during the who trip.
So the horizontal displacement of ball 2 is larger than the horizontal displacement of ball 1. :-)
I can't download this file |
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Fu-Kwun Hwang
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« Reply #10 on: October 13, 2007, 10:20:15 PM » |
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I just click the "get file for offline use" button, and I received the file in my email account.
I think there is a problem in your browser. Please change to another computer, may be it will work!
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lookang
Full Member
Posts: 223
http://sgeducation.co.nr
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« Reply #11 on: April 16, 2008, 03:23:26 PM » |
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« Last Edit: June 27, 2008, 01:25:13 PM by lookang »
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lookang
Full Member
Posts: 223
http://sgeducation.co.nr
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« Reply #12 on: June 27, 2008, 01:18:38 PM » |
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1. can check why i click download, it becomes check my email ? 2. how to get rid of this message? Emails send your account at [ XXXXXXXXXX@yahoo.com.sg] were returned at least 30 times, please check/modify your email address/email quota setting!  |
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Fu-Kwun Hwang
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« Reply #13 on: June 27, 2008, 02:02:30 PM » |
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I added code to check bounced email because a lot of user enter incorrect email which cause email sent out by our system were returned.
The records shown that at least 30 emails sent to you were returned by your mail server (for some unknown reason).
I just reset your record manually. It should work fine now.
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« Last Edit: June 27, 2008, 08:22:01 PM by Fu-Kwun Hwang »
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