A simple problem with the new version of Mathematica. (units)

Questions
,
1

Simple Question: I have just started using Mathematica 10. In the older versions using
Units was easier. Just << `Units and you could calculate F=m*a using grams and centimeters,
just like by hand. How do you do that in Mathematica 10 i.e. How do I calculate:

F= 10 gm * 980 cm/sec^2, and get an answer in dynes?

2

Hello!

UnitConvert[
Quantity[10, “Grams”]*Quantity[980, “Centimeters”]/
Quantity[(“Seconds”)^2], Quantity[“Dynes”]]

(for F= 10 g and not F= 10 gm)

3

Thanks for the quick response. That way of doing things makes sense, but it was a lot easier the old way. I suppose they
had their reasons for changing things, but it seems to me that at least leaving the easier, more straightforward way would be
a lot better. For instance, can you think what it would look like to use that kind of syntax to calculate the black body radiation
formula. Anyway, thanks. Your response really helped.

4

Syntax clumsy but at least the formula is built-in.

a = Quantity[4*10^14, "Hz"];
b = Quantity[273, "Kelvin"];
FormulaData[{"PlanckRadiationLaw",  "Frequency"}, {QuantityVariable["\[Nu]","Frequency"] -> a,  QuantityVariable["T","Temperature"] -> b}]

I(\[Nu])==2.728045498776555*10^-37 kg/(s)^2