Consists of a plated brass tube (so it's silver-colored) mounted on a piece of thick plexiglass. Three holes are drilled in the side at regular intervals.

To show different parabola paths of water in projectile motion and as an exercise in predicting range in projectiles. Also works well to illustrate how water pressure varies as a function of depth, and to show how flow rate varies as a function of pressure.

• Water trajectories cylinder
• Water tank (the one from ¹⁾ works well.)
• Adhesive tape

The metal cylinder has holes bored at a spacing such that when the cylinder is completely full to a height 4H then water is ejected at heights H, 2H and 3H Cover the three holes temporarily with tape and fill the cylinder with water. Then remove the tape, making sure that the water will drain into the tank.

If a tap is available in the room, it can be used to keep the water level topped up so that the trajectories of the water remain constant while you measure them or talk about them.