Turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

** Community Tip** - Did you know you can set a signature that will be added to all your posts? Set it here!
X

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Mute
- Printer Friendly Page

Dec 20, 2018
11:46 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
11:46 AM

Problem of solving Non-linear Differential Equations. Need help(mathcad15)

Hello,

I have been trying to solve this equation however no matter what I tried, I couldn't come up with an answer.

All the functions appearing in the differential equation is defined but at the end, it can not solve.

What is the problem?

I also included the file I am trying to solve.

Labels:

6 REPLIES 6

Dec 20, 2018
12:36 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
12:36 PM

You do not appear to have a function q(), but in your initial conditions you state q(0)=0 and q'(0)=0.

That should be at least confusing for the Mathcad solver.

Success!

Luc

Dec 20, 2018
12:38 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
12:38 PM

I realized afterward, but still, it is not solving...

Dec 20, 2018
01:44 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
01:44 PM

There may be more wrong. I could not see all of the file.

Please save the current state as a Mathcad 11 file, and attach.

Luc

Dec 20, 2018
01:48 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
01:48 PM

I am trying to get a q vs T plot. However, as in the equation, T is a function of dq/dt.

Dec 20, 2018
03:26 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 20, 2018
03:26 PM

1.

Please do NOT put your files in an archive, and certainly not in a RAR file (If you need to archive, use ZIP, I've experienced multiple occasions where Unrar produced errors). You can attach .mcd, .xmcd and .mcdx files directly, and you can add multiple files to a post (although that may require you to edit your post).

2.

You are still using q as a function and you have NOT defined that function. So dq/dt leads to nothing.

Once you have defined q(t), you can refer to its derivative, but then use dq(t)/dt, or (in a solve block) q'(t), but not dq/dt...

Success!

Luc

Dec 20, 2018
09:07 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator