(Solved): 24. A large tank of water is tapped a distance h below the water surface by a small pipe, as shown ...

24. A large tank of water is tapped a distance $h$ below the water surface by a small pipe, as shown in Figure 9-19. (a) Why is the pressure the same at points $a$ and $b$ ? (b) Show that the speed of the water emerging at point $b$ is $\sqrt{2gh}$ in the approximation that the speed at point $a$ is negligible. (This is known as Torricelli's law.) Why is this a good approximation?