Thank you very much! Why does this not work?
In[30]:= ClearAll[all]
z[t_] := Quantity[20, "Meters"/"Seconds"^2] t^2/2 +
Quantity[5, "Meters"/"Seconds"] t + Quantity[25, "Meters"]
z[Quantity[10, "Seconds"]]
Plot[z[t "Seconds"], {t, 0, 10}]
Quantity[1075, "Meters"]
The plot has the correct horizontal axis, the vertical axis goes from +1 to -1, and there is no curve.
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