Might the problem be that the head of the variable x in your expression sol:=.... is "Symbol"? Do you need to give it a numeric value? As suggested previously, you might get better insight as to what's going wrong if you develop and evaluate the code line-by-line with each line in a separate cell.

Here we go again! For some reason in the definition of velocity time is getting the units of s^2.

I figured it out.

Attachments:

Unit Plot.nb

That works! Thank you! Is there anywhere in the documentation I can find all this?

GOGO

Try this...

A notebook is also attached.

Here I've evaluated the Quantity[...] functions in place as I think it makes documents more readable. On a Mac, this is done by selecting the part of the expression you want to evaluate in place and pressing CMD-SHIFT-ENTER. Once evaluated, you can click into the Quantity panel and edit the numeric value. Alternatively, you can get a plain unit (without a value) by using the expression Quantity[None,"Unitname"]. Using this approach you can keep the quantity value outside the quantity panel. An example is given at the end of the attached notebook.

Hope this helps,

Ian

Attachments:

PlotWithUnits.nb

Try this...

A notebook is also attached.

Here I've evaluated the Quantity[...] functions in place as I think it makes documents more readable. On a Mac, this is done by selecting the part of the expression you want to evaluate in place and pressing CMD-SHIFT-ENTER. Once evaluated, you can click into the Quantity panel and edit the numeric value. Alternatively, you can get a plain unit (without a value) by using the expression Quantity[None,"Unitname"]. Using this approach you can keep the quantity value outside the quantity panel. An example is given at the end of the attached notebook.

Hope this helps,

Ian

Attachments:

PlotWithUnits.nb

Belated "Thank You." This has been very useful in evaluating functions but I don't have enough knowledge of Mathematica to extend it to other uses. For example when I try:

Plot[d[t], {t, Quantity[0, "Seconds"], Quantity[10, "Seconds"]}]

I get axes but no plot. Is there a part of the documentation I should read?

GOGO

You mean something like this?

d[t_]:=
    Quantity[20,"Meters"/"Seconds"^2]t^2/2+
    Quantity[5,"Meters"/"Seconds"]t+
    Quantity[25,"Meters"]

In[1]:= d[Quantity[13, "Seconds"]]
Out[1]= Quantity[1780, "Meters"]

In notebook it will look like: