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Collapsing Bottle

In this experiment you will discover the force of air pressure by making a plastic bottle collapse inward!

What you need:

  • Hot tap water
  • A small plastic water bottle (500mL)

What you do:

  1. Pour hot tap water into the plastic water bottle until it is about half-full.

2. Mix the water around for one minute.

3. Pour the water out and put the cap back on quickly.

Explore: What do you think will happen? 

Let’s Talk Science!

The hot water heated the air inside the bottle. When you poured the hot water out the air inside the bottle cooled down. Since cooler air takes up less space than warmer air, there was extra room in the bottle. To fill that extra space, the sides of the bottle were pushed in by the force of air pressure outside the bottle!1

Challenge 1

Try the experiment with a 1L or 2L plastic bottle. 


  1. Judy Breckenridge, Muriel Mandell, Anthony D. Fredericks and Louis V. Loeschnig (1998). 365 Super Science Experiments. Sterling Publishing Company, p.25

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