An ideal, incompressible fluid flows through a horizontal pipe with a constant volume flow rate. The graph shows the cross-sectional area \(A\) of the pipe versus the fluid velocity \(v\). In a wide section of the pipe, the fluid velocity is \(2.0 \text{ m/s}\). The fluid then flows into a narrower section that has a radius exactly half that of the wide section. What is the fluid velocity in the narrower section?