If I change g to

g := y -> piecewise(y>=eval(surf,x=(x(t))), 1, 0);

we get rid of the error but the ball still tunnels through the ground

@acer that sounds good, but just by modifying g to something like

g := y -> piecewise(y>=surf, 1, 0);

and changing deqs to

deqs := diff(y(t), t, t) = -g(y(t)), diff(x(t), t, t) = 0

However since surf is a function of x, the above won't work but probably something simple that needs adjustment because the error thrown after sol is

@acer ..

Hi Acer,using your events approach how do we use that to modify the BouncingBall application in the help applications so when we set C_R:=0.7 we don't run into the same problem of the ball tunnelling through the ground?

the application initially has

events = [[y(t) = eval(surf, x = x(t)), [temp = diff(x(t), t), diff(x(t), t) = V_reflect[1], diff(y(t), t) = subs(diff(x(t), t) = temp, V_reflect[2])]]]

The Python examples are working.  It is perhaps that Maple is functioning ok with the `failed to install` installed 2015 redistributable.  That is to say, enough of the 2015 redistributable package has been installed for Maple to function normally. 

There may be some back corner of Maple that I will never use that doesn't work, which I may never find out.

If the 2015 c++ redistributable were uninstalled, the Python examples may not work, I will try that when I make the time.

or complexplot(f(x),x=0.2..0.4)

@acer at work, I will have to check tomorrow.

I was hoping Maplesoft would provide some insight.  Or maybe no one really knows?

@Rouben Rostamian  interesting solution.  I didn't realize as the oscillations got smaller they become a problem - it could be used to solve the ball bouncing application https://www.mapleprimes.com/questions/203742-Bouncing-Ball-Application-Problem- on hilly terrain in which the model fails when, as I now know, the oscillations of the ball become too small. 

I think setting the piecewise g=0 at y<0 becomes more difficult when y becomes a function of x.

@digerdiga You're welcome, I think :)

@digerdiga for your particular example, just expanding on what Kitonum did.  Created a little procedure

confine:=proc(a)
   %sqrt((a/(select(has,a,exp)))^2)*select(has,a,exp)
end proc:

Your second example equation
ex:=sqrt(x)/2h*exp(-x^2/2*epsilon)
                                

confine(ex)
                              

And on your first example equation

ex1:=sqrt(x)/2h

confine(ex1)

@digerdiga so just to verify what you want.  You want to take an expression given, and then force/manipulate it into an expression involving just the exponential and radical?

@Preben Alsholm .. Maple V Release 3, that was indeed a great one!

A Danish cabbage dish .. that's funny.  Ok shouldn't use that one.  On second thought then I suppose it shouldn't be too extravagant either.  Speaking about Christmas, the Wolfram splash screen looks like a Christmas ornament and the wordle theme makes it very cluttered. 

Maple 10 and 11 were interesting.  I guess then it's maybe best to keep the splash screen simple.

@Konstantin@ .. regarding zoom factor you'll have to think creatively, you can use font sizes for a workaround.  Combining font size and zoom factor I'm sure you can find a good size for text on the screen. 

Is it the fact that you can't get the perfectly exact size of lettering on your screen?  Or is it the fact that viewing your page can't be adjusted in continuous fashion?

edit added *** as Daniel Skoog just described above I think is perfect for your needs.  CRTL + mouse scroll

Is it understanding the proof?

That is are you trying to understand why   ( A*B mod N ) = (A mod N)*(B mod N) mod N    ?

Indeed a chemical theme might have been more fun.  Now that you mention a vision chart it looks almost exactly that.  The font certainly looks the same as those eye test charts, I should have initially made it into the block characters the Boggle game has. 

I will think of something more chemistry or nuclear physics related for my next project. This one was rather light.