Tell me more ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.
up vote 0 down vote favorite

I am making a game where you have large number of balls on a plate and the plate can be moved left or right. I want the balls on the plate to swing left and right.

I guess this can be considered as a pendulum with a moving pivot point.

I know; the distance to sphere , distance pivot has moved in time t

can anyone provide some help on how to calculate the position of the sphere?

share|improve this question
2  
It's not clear to me at all what system you're trying to model. You talk about a sphere--what sphere? Do you mean to each ball (which would be several spheres, not just one)? – Muphrid Feb 2 at 7:44
I just explained what my overall problem is so it is clear what i wanted to do; I just wanted the equation for one point (ball) say distance L from the moving pivot point. If the pivot point moved distance d at time t. I want to know how to find the locations of the ball. – Janaka Feb 2 at 10:25
It is not clear to me neither. But for any constrained problem use Euler-Lagrange equations. en.wikipedia.org/wiki/Euler%E2%80%93Lagrange_equaton Plus do not expect nice equation in time. You probably end up numaricaly integrating some sort of differential equation. – tom Feb 2 at 10:54
using a differential equations not going to work in this my case. Just to clear things up, If you have a pendulum and if the fix point move some distance, what happen to the pendulum? Do I have to use differential equations to find the position of the pendulum? Since this is for a game, I don't necessarily need very accurate calculation. I need to give a impression of a swinging action. Is there a simple mechanism I can use for this? – Janaka Feb 2 at 11:27
it seems clear for you, but after reading the question I have no idea of what system you have in mind (what would be the pivot? or the pendulum, and how an why it moves? ). If you can make an effort to explain it better, we could try to fin a good simple approximation – julian fernandez Feb 19 at 2:55

1 Answer

up vote 0 down vote

Equations you look for are here http://www.scribd.com/doc/104338777/14/Pendulum-with-a-free-support see 6.169

share|improve this answer
thank you very much for your answer. Honestly these equations are little beyond me :) is there any way you can simplify it for me? I have the information x,l,M,m in the web page. If you can tell me how angle theta change with time that would be really helpful. – Janaka Feb 2 at 14:12
well for small angles you can use equations 6.174 – tom Feb 2 at 15:40

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.