Motion of Projectile App
 

I wrote a javascript app that visualizes the motion of the ball with adjustable parameters like angle and initial velocity. The app seems to work best in Chrome.

http://hostedfiles.x10.mx/2/2014ball.html

Please feel free to let me know of any issues with the app. Also, you can double check my maths to see if I made any mistakes. I used the formulas from here

I wasn't sure of the terminal velocity. The terminal velocity parameter is used to compute the amount of drag on the ball. Currently the value I'm using is 51.33 which I found is the terminal velocity of a volleyball, so its likely going to be less than that.

Re: Motion of Projectile App
 

Thanks for making the App!

I just want to know, would it be possible for you to change the input such that we can type in our own figures, instead of using the dial, to increase calculation accuracy?

Re: Motion of Projectile App
 

I believe the terminal velocity is closer to 11.37 m/s.

Edit: That's 36.09 f/s. Sorry, I've always been taught to do all my physics in metric.

Re: Motion of Projectile App
 

Nice work. I couldn't have programmed that.

I do agree with Edxu that changing the values via keyboard instead of a scroll bar would be more convenient. Would your math still work with decimal values?

Re: Motion of Projectile App
 

Done!

Re: Motion of Projectile App
 

Thank you for making this app. It will be very helpful.

Re: Motion of Projectile App
 

Caveat utilitor. Quoting from the source:

Suppose, further, that, in addition to the force of gravity, the projectile is subject to an air resistance force which acts in the opposite direction to its instantaneous direction of motion, and whose magnitude is directly proportional to its instantaneous speed. This is not a particularly accurate model of the drag force due to air resistance (the magnitude of the drag force is typically proportion to the square of the speed),

For a given launch speed, you can probably empirically find a value for "c" which is a good compromise. But if you change the launch speed significantly, that empirical value for c may no longer be a good approximation at the changed speed.

It would be interesting to compare the results of the above model to other models recently posted here on CD which implement drag proportional to speed squared.