An incompressible, nonviscous fluid is initially at rest in the vertical portion of the pipe shown in Figure P14.67a, where $L=2.00 \mathrm{m}$ . When the valve is opened, the fluid flows into the horizontal section of the pipe. What is the speed of the fluid when it is all in the horizontal section as shown in Figure $\mathrm{P} 14.67 \mathrm{b}$ ? Assume the cross-sectional area of the entire pipe is constant.