# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## JDK1.0.2 simulations (1996-2001) => kinematics => Topic started by: Fu-Kwun Hwang on March 11, 2006, 03:58:45 pm

 Title: Bouncing Ball Post by: Fu-Kwun Hwang on March 11, 2006, 03:58:45 pm Bouncing BallsSome balls bounce better than others.A particular ball can be characterized by itscoefficient of restitution:The ratio of its rebound speed Vf to its collision speedViwhen its bounces off a hard, stationary surface that can't move.coefficient of restitution r = Vf /ViScientists have found that, for most balls, this speed ratioremains constant over a wide range of collision speeds.The amount of kinetic energy transformed at impact is calledthe collision energy (become thermal energy).This java applet shows you the effects due todifferent coefficient of restitution.1. You can enter different value of coefficient of restitution as(Vo/Vi).Then, press return key to start the animation.2. You can change the initial velocity Vx of the ball.Click near the tip of bluearrow( represent its velocity)and drag it left/right.3. You can change the initial height  (drag it up and down with mouseleft click)4. Press Start button to start/restart animation.The animation will stop automatically when it bounces off the screen.4. Press Reset button to reset parameters to its default value.It also clear the screen.5. Press the mouse button to pause the animationIf you click the left mouse button,animation will resume when you release it.If you click the right mouse button,you need to click it again to resume.6. The mouse coordinate (X,Y) will be shown when its inside the window.You will know the timing t from (X and velocity Vx) Title: Dr. P. Radhakrishnamurty Post by: rkmp06@dataone.in on December 23, 2006, 01:09:24 pm Dear Sir,Would you please give the definition (mathematical expression) of coefficient of restitution in terms of the velocities of masses before and after collision?Is the kinetic energy of the system consisting of the two masses conserved in an elastic collision?I suppose you are stating that some of the kinetic energy gets transformed into heat and is lost from the system when the collision is inelastic. I want you to confirm this please. Title: Re: Bouncing Ball Post by: blinx on March 27, 2007, 02:56:07 am It is possible to get source code? Title: Re: Dr. P. Radhakrishnamurty Post by: Fu-Kwun Hwang on March 27, 2007, 09:20:01 am Quote from: rkmp06@dataone.in on December 23, 2006, 01:09:24 pmDear Sir,Would you please give the definition (mathematical expression) of coefficient of restitution in terms of the velocities of masses before and after collision?Is the kinetic energy of the system consisting of the two masses conserved in an elastic collision?I suppose you are stating that some of the kinetic energy gets transformed into heat and is lost from the system when the collision is inelastic. I want you to confirm this please.For the above simulation:The ratio of its rebound speed Vf to its collision speed Vi (coefficient of restitution) is kept as a constant value ,when its bounces off a hard, stationary surface that can't move.The default value is 0.8 In this case, 36% of kinetic energy(before bouncing) is loss each time. Title: Re: Bouncing Ball Post by: Fu-Kwun Hwang on March 27, 2007, 09:22:33 am Quote from: blinx on March 27, 2007, 02:56:07 amIt is possible to get source code?For all the simulations created with EJS in this forum, you will be able to see the ejs source if you click "load ejs as signed applet".Please check out another category to view simulations created with EJS. Title: Re: Bouncing Ball Post by: blinx on March 28, 2007, 03:27:53 pm Thank you, I found Bouncing ball in EJS category Title: Re: Bouncing Ball Post by: janelavis on September 22, 2009, 01:55:42 pm Well, I'd be tempted to flat-out animate it. I guess you could try one of those existing bouncing ball expressions, take every constant built into the expression and pick-whip it to a slider value. Then you have to change the sliders every moment the ball gets kicked. Title: Re: Bouncing Ball Post by: mazni_y on March 23, 2011, 10:41:08 am hi...can i get the source code for this topic...hope u can send it to my email.. Title: Re: Bouncing Ball Post by: ahmedelshfie on March 23, 2011, 05:31:19 pm You can download the source code by your self, you will find up the applet option allowed you download source code, choose first download file and after click Get files for offline useI attach image explain how you download source code for any applet in NTNU.(http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=345.0;attach=4079;image) Title: Re: Bouncing Ball Post by: phoenx on July 20, 2012, 10:31:57 am Little confuse about what formula did you use in this applet.. Title: Re: Bouncing Ball Post by: nayemkhulna on July 20, 2012, 07:17:36 pm Hello,I am new this forum and i am learning about.Thanks.-*- Title: Re: Bouncing Ball Post by: moobeenan on September 19, 2012, 09:52:30 am hello hello hello hello.......... :D :D :D Title: Re: Bouncing Ball Post by: beebeeoa11 on September 24, 2012, 03:02:37 pm  ??? ??? ??? ??? ??? Title: Re: Bouncing Ball Post by: beebeeoa11 on September 26, 2012, 04:45:52 pm Always refreshing to hear a rational answer Title: Re: Bouncing Ball Post by: beebeeoa11 on September 26, 2012, 04:47:26 pm  >:(Always refreshing to hear a rational answer Title: Re: Bouncing Ball Post by: garymauricio on February 12, 2015, 02:33:27 pm Hi Guys,I am also new to this forum. I want to know more information from your site. I want to learn more in physics so only I joined here. Hereafter I will ask more questions now only I started reading your blog so I canâ€™t able to ask more questions now itself. Now I have clear idea about kinetic energy and how to calculate the coefficient of restitution. Thank you keep posting more information. -*- Title: Re: Bouncing Ball Post by: chengfu on October 26, 2015, 04:06:23 pm Yes! it's really great tutorial :) Title: Re: Bouncing Ball Post by: oldgamer on December 21, 2015, 12:34:35 am Quote from: Fu-Kwun Hwang on March 11, 2006, 03:58:45 pm
Bouncing Balls

Some balls bounce better than others.

A particular ball can be characterized by its

coefficient of restitution:
The ratio of its rebound speed Vf to its collision speedVi
when its bounces off a hard, stationary surface that can't move.
coefficient of restitution r = Vf /Vi
Scientists have found that, for most balls, this speed ratio
remains constant over a wide range of collision speeds.
The amount of kinetic energy transformed at impact is called
the collision energy (become thermal energy).
This java applet shows you the effects due to
different coefficient of restitution.

1. You can enter different value of coefficient of restitution as(Vo/Vi).

Then, press return key to start the animation.
2. You can change the initial velocity Vx of the ball.
Click near the tip of bluearrow( represent its velocity)
and drag it left/right.
3. You can change the initial height  (drag it up and down with mouseleft click)

4. Press Start button to start/restart animation.

The animation will stop automatically when it bounces off the screen.
4. Press Reset button to reset parameters to its default value.
It also clear the screen.
5. Press the mouse button to pause the animation
If you click the left mouse button,
animation will resume when you release it.
If you click the right mouse button,
you need to click it again to resume.
6. The mouse coordinate (X,Y) will be shown when its inside the window.
You will know the timing t from (X and velocity Vx)
Hi, I know this is old but could anyone compile it for me...i want keep and use it offline. Thanks in advance.