Dynamics Help

Forum|Forum|7 years ago
February 25, 2019
4 replies
3020 views

Hello! I am new to the PTC forums, but I had a question regarding how to format a particular differential equation into Mathcad Prime. My equation is: ads=integral(v) dv Below is a screenshot of what I have so far, but it is using my guess value as the solution, when the actual solution for Vo is 15.5 ft/s. Acceleration, a, is given to be constant at 12 ft/s^2, initial displacement, So, is given to be 0 ft, final displacement, Sf, is given to be 140 ft, final velocity, Vf, is 60 ft/s. That leaves initial velocity, Vo. The basic form of the differential equation I am employing goes a*ds=integral (v) dv where ds is the differential for displacement and dv for velocity. Any help regarding this formatting would be greatly appreciated guys! Thanks!

mathcad practice with problem statement.PNG

mathcad practice.PNG

Best answer by LucMeekes

Sort of like this:

(I'm using a different Mathcad, so it looks different )

Success!
Luc

L

LucMeekes

23-Emerald IV

I'm afraid the picture does not make clear what exactly you are trying to solve.

What is the problem description:

- what do you know (which variables and/or constants do you the value of),

- what do you need to find (what is the unknown value or function), and

- what is the expression or equation involving the knowns and the unknowns?

Do not just post a picture, preferrably post (also) the worksheet.

Success,

Luc

L

LucMeekes

23-Emerald IV

You should take away the v:=... and s:=... definitions from the Constraints (middle) part of the Solve block. (Definitions aren't allowed in that part)

In the Solver (lower) part you should have: Find(v0)=.

That should to it.

Success!
Luc

L

LucMeekes

Answer

23-Emerald IV

Sort of like this:

(I'm using a different Mathcad, so it looks different )

Success!
Luc