Why does the following expression not simplify?

During some computation, I sometimes stumble upon expressions such as:

expr = 1.4`*^-16 Sqrt[-4.`*^31 x3^2 Cos[0.1` T]^2 Sin[1.` T]^2 + 
9.`*^31 x3 x4 Cos[0.6` T] Sin[0.6` T] Sin[1.6` T]^2]

This is something like $10^{-16}\sqrt{10^{32}A}$ and I hoped it would Simplify to $\sqrt{A}$.

Why isn't the $10^{-16}$ in front of the Sqrt passed into the Sqrt so that the powers of 10 disappear?

Additionally, it seems very dangerous since

Chop[expr]

return 0.!

Is there a simple way to force MMA simplify the expression?

Comments

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