       Re: need help determined time to travel a path

• To: mathgroup at smc.vnet.net
• Subject: [mg107549] Re: [mg107512] need help determined time to travel a path
• From: Tomas Garza <tgarza10 at msn.com>
• Date: Tue, 16 Feb 2010 03:55:31 -0500 (EST)
• References: <201002151047.FAA28291@smc.vnet.net>

```What is g? What is time0? Also, pi should be capitalized (pi).

Tomas

> Date: Mon, 15 Feb 2010 05:47:53 -0500
> Subject: [mg107512] need help determined time to travel a path
> To: mathgroup at smc.vnet.net
>
> I am trying to determine the time to travel a circular path. This path is=
on a
> circle. It's fairly easy to understand.
>
> But, I can't seem to figure out why this is failing.
>
> (* define my parametrizations *)
> circlex[t_]:=13+13*Sin[t+pi];
> circley[t_]:=13+13*Cos[t+pi];
>
> (* the derivatives *)
> dcirx[t_]:=D[circlex[t],t];
> dciry[t_]:=D[circley[t],t];
>
>
> (* amount of time needed to travel a circle *)
> Integrate[Sqrt[(dcirx[t])^2+(dciry[t])^2]/Sqrt[2*g*(circley[time0]-
> circley[t])], {t, 0.01, pi/2}]
>
> I get a negative value for the time. This can't be right..
>
> Any help is much appreciated!!
>
> Thanks.
>