PURPOSE: To show that static pressure is a function of the depth. Or, to show that the range of a water jet from a tank is a maximum at the middle of the tank.
DESCRIPTION: A large tank with holes stopped by corks is filled with water. When the corks are released the water jets emerge from the side of the tank. The range of each jet is determined by its depth. The bottom jet emerges with the greatest pressure. The top jet emerges with the lowest pressure.
Note that this demo can also be used to show that the range of a velocity efflux from a tank is greatest in the middle. The range of each jet is measured from the level of the bottom of the container. The middle jet has the greatest range. Each pair of jets above and below the middle jet has the same range. The range of each jet gets smaller the further the jet is from the middle.
This demo goes by the names of 'Toricelli's Tube', 'Mariotte's Bottle' and
'Velocity Efflux'.
Click Here to Download Video (3.2 MB)
EQUIPMENT: Toricelli's bottle is stored in the Fluid Mechanics cabinet. Dye
may be added to the water for visibility. A cinder block or wooden riser is used to
raise the level of the bottle and a water guide is used to direct the water into the sink.
SETUP NOTES: The tank takes 15 minutes to fill. It is heavy and hard to move when full. It will splash water onto the floor unless you move it very slowly.
Updated by LKT 8/3/05.