How do I use symbolic variables with Unitful?

[NightMachinery]

I am trying to do some basic Physics problems using Julia. I have had some success using Unitful, but I do not know how I can solve problems for general parameters (i.e., get a closed form of the solution in terms of the missing variables).

E.g., I want to do something like:

force(m, a) = m*a

m = 10u"kg"
@symbol a # pseudocode
a = (a)u"m/s^2" # give it a unit
print(force(m, a))

This should print 10*a N. (N is Newton, defined by Unitful).

Of course, this example is trivial, but it is more interesting in bigger problems.

Also posted to the discourse.

[lukebemish]

Unitful isn't really a library to do symbolic algebra, simply a library to express units. However, if you'd like to instead solve/express stuff like this in a way a regression tool of some sort could solve, you could certainly just set up a lambda expression:

force(m, a) = m*a

m = 10u"kg"
force_equation = a -> force(m, a*u"m/s^2")

If you really want a symbolic algebra system, there certainly are symbolic algebra systems for Julia, though I haven't used any of them much; Symbolics.jl is one If you want any compatibility between these packages and Unitful, though, you'll likely have to implement it yourself; it would probably need to sit on the side of the symbolic algebra package, as that package would have to understand how to deal with units in expressions.

[phpsmarter]

Here is some code using Symbolics,Plots, PlutoUI,Latexify,Unitful,UnitfulLatexify

let
	@variables Work, heat,junit,weight, g,h,n,x
	heat=(2.00*10^6)u"cal"
	junit=4.186u"J/cal"
	g=9.80u"m/s^2"
	weight=50u"kg"
	h=2u"m"
	Work=heat*junit
        n=Work/(weight*g*h)
       latexify(:(n=Work/(weight*g*h)=$n))
end

let
	
	heat,g, j,weight,height=(2.00*10^6)u"cal",9.82u"m/s^2",4.186u"J/cal",50u"kg",2u"m"

	latexify([heat,g, j,weight,height])
end

let
	a = 9.82u"m/s^2"
        t = 4u"s"
        x = a*t^2
       latexify(:(x = a*t^2 = $x))
end