Why does the result not include radians in the solution for a? This does not occur if I use meters instead of radians.

NSolve[{Quantity[11.2, ("Radians")/("Seconds")] == a t, 
  t == Quantity[2.92, "Seconds"], d == .5 a t^2}, {a, t, d}]


{{t -> Quantity[2.92, "Seconds"], 
  a -> Quantity[3.83562, 1/("Seconds")^2], d -> 16.352}}
  • 1
    $\begingroup$ Simpler example: Solve[w == Quantity[11.2, ("Radians")/("Seconds")], w]. Of course one definition of radian measure is (arc length)/(radius), which is dimensionless. $\endgroup$
    – Michael E2
    Oct 26, 2016 at 2:29
  • $\begingroup$ I see. What if I have a system of equations with radians and revolutions? Will Mathematica distinguish and convert between the two? $\endgroup$ Oct 26, 2016 at 2:32
  • $\begingroup$ It seems to: Solve[w == Quantity[11.2, ("Revolutions")/("Seconds")], w]. I only suggested it because I don't know for sure how Mathematica treats "Radians". But it looks like Solve converts revolutions to (unitless) radians. $\endgroup$
    – Michael E2
    Oct 26, 2016 at 2:37
  • $\begingroup$ It looks like "Revolutions" is automatically multiplied by 2\[Pi] $\endgroup$ Oct 26, 2016 at 2:43
  • $\begingroup$ Yes, just so. It seems to happen automatically in Solve or NSolve. I don't know what you can do, if you do not want that to happen. $\endgroup$
    – Michael E2
    Oct 26, 2016 at 2:46

1 Answer 1


Radians are a dimensionless quantity


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