Thursday, June 5, 2014

Air Pressure: Making a Bottle Water Fountain

Jelly Bean and Jumping Bean have been rather fond of balloons lately, and what I mean about rather fond of, is obsessed.  And now that it is summer, they love playing with water outside.  So, when I saw this activity at Life with Moore Babies, we had to do it!  We are going to investigate air pressure using these favorite things (balloons and water).

We gathered up our supplies from around the house: empty water bottle, funnel, straw and balloons and with minimal preparation we began our investigation.

First, we talked about how air is all around us.  I asked Jelly Bean and Jumping Bean what is inside a balloon when I blow it up.  "AIR!"  they both yelled.  We discussed how even though it is invisible, or you can't see it, air is still there.  To demonstrate this concept, a blown up balloon was attached to the mouth of a plastic bottle.  The girls were amazed that the balloon did not deflate.  The air inside the "empty" bottle was applying pressure, or pushing against the air inside the balloon.  Therefore, the air inside the balloon did not come out making the balloon whiz all around.

To demonstrate the air pressure even further, Jelly Bean and Jumping Bean made a water fountain by exploring what happened when you applied air pressure to a bottle filled with water.

First, they poured water into a plastic bottle with food coloring for fun!  We used a funnel just to make it a little easier!  I had pre-cut the bottle with a small hole cut in the side and secured a straw through the hole with clay (to seal any leaks).  One note: make sure your straw is pointing up so that the water does not flow out.  Then, an inflated balloon was attached to the mouth of the bottle.

Once the balloon was released, the air pressure from the balloon caused the water to flow out of the attached straw.  That was a lot of fun to watch, and we did it over and over again!


  • plastic bottle
  • balloon
  • straw
  • water
  • funnel optional
  • clay


  1. Blow up a balloon, and ask what is inside. 
  2. Attach the balloon to the mouth of an empty plastic bottle.
  3. Discuss that the balloon remains inflated because there is air in both the balloon and the bottle.  There isn't any room for the air to go when the balloon is released so it stays inflated.
  4. Attach a straw to the plastic bottle by poking a hole in the bottle and sliding the straw inside.  Make sure the straw is pointing up.
  5. Press clay around the hole and straw to seal anywhere that may leak. (ours leaked so we added more clay)
  6. Pour water into the bottle.
  7. Place an inflated balloon over the mouth of the plastic bottle.
  8. Let go of the balloon.
  9. Watch the water flow out of the straw making a fountain.
  10. Repeat.

No comments:

Post a Comment

Thank you for your comment.