Water levels and rooftop tanks

In the picture

1. 1The left water surface in the U-shaped tube: it rests at the same height as the right water surface.
2. 2The right water surface in the U-shaped tube: it rests at the same height as the left water surface.
3. 3The rooftop tank: a high container that holds water above the building.
4. 4The top-floor faucet: an outlet near the tank, reached by water flowing down the pipe.
5. 5The ground-floor faucet: an outlet lower in the building, reached through the same pipe.

Examples

• A rooftop water tank feeding a bathroom tap.
• Two clear cups joined by a tube, with water settling at one level.

Quiz: Water levels and rooftop tanks (Age 12)

1. 1

   In connected containers where water can flow freely, how do the water surfaces settle?

   • They become higher in the smaller container.
   • They settle at the same height.
   • They stay only in the higher container.
2. 2

   What does a taller water column do to the pressure at an outlet?

   • It pushes water out with more pressure.
   • It makes the water flow backward.
   • It has no effect on the pressure.
3. 3

   Why can a rooftop tank supply water to faucets below it?

   • The height of the water above the faucet creates pressure.
   • The tank pulls water up from the ground.
   • The faucets make their own water pressure.

The answers, each with its explanation, are in the app. This quiz is free there while the lesson is in the free week.