Water has a pressure of 3.00 x 105 pa and a speed of 1.00 m/s as it flows through a horizontal pipe. at a certain point, the pipe narrows to one-fourth its original diameter. (remember the radius is half of the diameter, so its radius will also be one-fourth its original size.) what is the speed of the water flow in the narrow section of the pipe? . a.. 16.0 m/s. c.. 16.2 m/s. b.. 12.6 m/s. d.. 22.6 m/s