What You Need Small paper cup

Empty detergent bottle or soda bottle

Water

Tissue paper

Directions

After moistening the tissue paper with water, use it to plug the hole in the top of the detergent bottle.

Flip the cup upside down and place it over the top of the bottle.

Squeeze the bottle and tell students to watch what happens.

• What happened?

• Were the forces balanced or unbalanced?

Explain how this relates to Newton’s first law of motion.