If there is a hole in a water tank, water will shot out due to water pressure.
You can drag the hole up and down to change its position.

Click show baseline checkbox, drag the hole up and down , and find out when the horizontal displacement is maximum?

VIEW or DOWNLOAD ejs xml source
then click to translate strings for selected locale.

Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop.

Relation between horizontal velocity vx and height h(height between water level and the hole).

\rho g h =\frac{1}{2} \rho v_x^2 , so vx=\sqrt{2\,g\, h}