S3.7.8 For the adult
Pressure in water and air
Why does water shoot out of a bottle, and why does it go farthest from the lowest hole?
What this chapter teaches
Water pressure grows with depth and pushes in every direction. Air pressure pushes a drink up a straw once the pressure inside is lowered, and a thing floats when the upthrust equals its weight.
Three questions to ask
There is no one right wording. Listen for the idea.
- Why does the lowest hole in a bottle send out the fastest jet?
- What really pushes a drink up a straw?
- When does a thing float? What is balanced?
After the chapter, the learner can
- Show that water pressure grows with depth using a bottle with holes
- Explain how air pressure lets you drink through a straw
- Explain floating as an upward push balancing weight
What they copy into their notebook
Water pressure grows with depth and pushes in every direction. Air pressure pushes a drink up a straw. A thing floats when the upthrust equals its weight.