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?
Thank you!
Thanks
But with error!
What error? It opens with no problems in my Prime 2 Express...
Sorry!
Prime Express can not work with the Odesolve function.
I have an error by Odesolve function in my Prime 5!
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.
Help please!
May be the math model is wrong?
If t.end is very small I have solution.
Now I have not 4 but 3 equation!
Help please!
See please attach
sorry luc
I do not ask to convert 15 into prime
I ask to help me in solution
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):
Alan
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!
Thanks, Alan!
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).
Alan
Great response!
Just one correction:
Not sure I understand Fred:
Alan
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?
Fred,
See my earlier reply above (reply number 9 I think), where I develop a model with the string attached to an axle.
Alan
Thanks? Alan and Fred!
But I would like know why my model with 4 equations not work.
Deleted as irrelevant!
Alan
Sorry,Alan!
I have two 2-d order ODEs, not 4 1-st order ODEs
Deleted. My previous comment here was beside the point!
Alan
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:
Alan
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:
One last addition:
Two full cycles and a string impulse calculation.