Leaky Water Bottle

Leaky Bottle (6)

This easy STEM experiment has major wow factor, even for grown-ups!

In an empty water bottle, poke three small holes with a needle, one atop the other. Many water bottles these days are made of incredibly thick plastic: you’ll want to look for good old-fashioned thin plastic bottles if you’re going to pierce through with the needle easily.

Leaky Bottle (1)

We added a little blue food coloring to the empty bottle just for fun, although the experiment will work just fine with clear water.

Leaky Bottle

Begin pouring water in (a watering can is helpful to use), and of course water will begin trickling out of your three holes slowly. Once your bottle is full, twist on the cap.

Leaky Bottle (2)

The water stops leaking out!

Leaky Bottle (4)

After your child’s initial moment of wow, you can explain what’s going on: the bottle contains both air and water, but for more water to be pushed out, more air has to come in. Once the cap is on, the water molecules bunch together and create enough surface tensions against the tiny holes from the needle. If the holes were any larger, of course, this wouldn’t work so well! Then, once the cap is off, more air comes in and pushes the water right out again.

Leaky Bottle (5)

With that explanation out of the way, now Travis wanted to twist the cap on and twist the cap off over and over… Through three refills of the bottle!

Leaky Bottle (7)

There might have been a giggle factor to this project, too, since yes the bottle looks a bit like it’s going to the bathroom when the stream of water arcs out.

Leaky Bottle (8)

As you can see, both my kids were rapt! A fantastic STEM experiment outside on a hot day.

Leaky Bottle (3)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s