I would like to create the digital double of the yo-yo toy
Were is my error? See please attachs MC15 & Prime 5.
Do you know someone?
See please new version of sheets in attach.
Mathcad 15 gives as more informative error message.
Mathcad Prime 5 gives as old not informative error message.
May be the math model is wrong?
Hmm! I'm not sure I like your yoyo Val, so I've come up with one of my own! See below and the attached (M15 version):
I know! I know! I haven't included units. I haven't provided an animation. I haven't done the upward movement. I'll leave that to whoever is interested!
I am glad that I gave you the pleasure to solve this problem.
But I would like to see ODEs solution - not problem, but SuperProblem!
Why me sheets with Odesolve have errors?
Ok Val, I've modified your worksheet so that it works. The solver was confused in particular by F(t) and the explicit inclusion of the energy equation (which is there implicitly in the other terms). See my modifications below, and the attached for the complete file (M15).
Sorry! I missed your substitution. You (and Val, it seems) both assumed the string was wound on the outside of the yoyo. You made no mistake, it was my omission. What happens if the axle of the yoyo is much smaller than the outside of the yoyo?
I've been thinking about this a little more. My previous replies were too glib (i.e. wrong!). I now think the problem is as follows:
I have neither Mathcad 15 nor a full Prime, so OdeSolve is beyond me.
But, I think what you're missing is tying angular rotation together with vertical motion: