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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 num_plates_ET(q_plant, W_chan):
 """Return the number of plates in the entrance tank. This number minimizes the total length of the plate settler unit. Parameters q_plant: float Plant flow rate W_chan: float Width of channel Returns ------- float ? Examples -------- 1.0 """

    num_plates = np.ceil(np.sqrt(q_plant / (design.ent_tank.CENTER_PLATE_DIST.magnitude
                                            * W_chan * design.ent_tank.CAPTURE_BOD_VEL.magnitude * np.sin(
                design.ent_tank.PLATE_ANGLE.to(u.rad).magnitude))))
    return num_plates