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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _len_tube(Flow, Diam, HeadLoss, conc_chem, temp, en_chem, KMinor):
 """Length of tube required to get desired head loss at maximum flow based on the Hagen-Poiseuille equation."""

    num1 = pc.gravity.magnitude * HeadLoss * np.pi * (Diam**4)
    denom1 = 128 * viscosity_kinematic_chem(conc_chem, temp, en_chem) * Flow
    num2 = Flow * KMinor
    denom2 = 16 * np.pi * viscosity_kinematic_chem(conc_chem, temp, en_chem)
    len = ((num1/denom1) - (num2/denom2))
    return len.magnitude