Why is the water Pressure dropping?
water pressure in a water tower
This fun water activity shows how water pressure is affected by the amount of water in a water tower. See how the water pressure drops as the water tower is emptied of water.
- Adult helper
- 2-liter plastic pop bottle
- 16 penny box nail
- Hot pad
- Large tin can (29oz size)
- Plastic container
- Have an adult help you make three holes in the side of the 2-liter
- Take a hot pad to hold the nail while heating the tip of the
nail. (We used a candle to heat the nail's tip then pressed it into the
bottle while it was resting on its side.)
- The two holes should be
abou 7 cm apart. Make the lower hole about 5 cm from the
bottom of the bottle.
- Cover the holes with tape so the
water will not leak out.
- Fill the bottle with water and recap the
bottle while setting up the experiment.
- Place the plastic container in
an area that will not be affected if some of the water leaks during the
- Place the tin can next to the container and the pop bottle
on top of it.
- Make a guess as to which hole will shoot a jet of water
the greatest distance?
- Remove the lid from the top of
the pop bottle. Pull the tape off so the holes are exposed. If you are
having trouble making the activity work it might be because you left the
cap on the bottle.
- Watch how the streams of water change as the water
My Water Cycle activity book contains fun activities for people of all ages. The book is available as an ebook that contains 46 pages of interesting and fun activities. Myrna Martin
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Science behind the activity
Water pressure increases as you go down in depth. That is why the water
pressure at the greatest distance. As the water pressure decreases the water
jets decrease in length until they stop flowing.
Towns with water towers
use this same principal to move water from the tower to homes and
businesses all around the town. The tanks are built to keep an entire days worth of water in the tank in case of an emergency.
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