Re: Why No Solution Using Solve?

• To: mathgroup at smc.vnet.net
• Subject: [mg33931] Re: [mg33902] Why No Solution Using Solve?
• From: "Eric L. Strobel" <fyzycyst at comcast.net>
• Date: Tue, 23 Apr 2002 07:14:19 -0400 (EDT)
• Reply-to: fyzycyst at mailaps.org
• Sender: owner-wri-mathgroup at wolfram.com

```on 4/22/02 12:57 AM, Tom Compton at comptont at concentric.net wrote:

> Why doesn't this give a solution?
>
> Solve[{
> m1 a1 == P1/ v1 - A1 Rho Cd (v1 + w)^2 /2 - m1 g Cr1 - m1 g S,
> m2 a2 == P2/ v2 - A2 Rho Cd (v2 + w)^2 /2 - m2 g Cr1 - m2 g S,
> m3 a3 == P3/ v3 - A3 Rho Cd (v3 + w)^2 /2 - m3 g Cr1 - m3 g S},
> {Cr1, S, w}
> ]
>

I'm sure others will answer the algebra question, but what caught my eye was
that these look like equations of motion, which are usually stated as
differential equations. Perhaps if you describe the physics problem you're
trying to solve?

BTW, I notice that you don't really have separate quantities Cr1 & S, but
rather a single quantity (Cr1 - S), so you're really only solving for two
variables.

- Eric.
--

Eric Strobel (fyzycyst at NOSPAM^mailaps.org)

=====================================================================
Design is an iterative process. The necessary number of iterations is
one more  than the number you have currently done. This is true at any
point in time.
=====================================================================

```

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