The Extraordinary Properties of Water

1. The Extraordinary Properties of Water

2. Cohesion • Attraction between particles of the same substance • - why water is attracted to itself • Results in:Surface tension (a measure of the strength of water’s surface) • surface film on water • -allows insects to walk on the surface of water

3. Water: Cohesion • Water bugs walk on water • Drops of water on a penny • Bottles don’t overflow immediately • Water “beads” on newly a waxed car

5. How will this affect your boat? CohesiveWater molecules will stick together to create surface tension. Therefore - Cardboard should float on the water. • ALSO:::: Cardboard has a lower DENSITYlevelthan water Objects with less density than water - -- FLOAT Objects with more density than water - -- SINK Density = mass / volume

6. Adhesion • Attraction between two different substances • - water will bond with other • surfaces such as glass, soil, • plant tissues, and cotton. • Adhesion results in: • Capillaryaction- Occurs because water is “sticky”. It’s the flow of liquids through-out a substance - can defy gravity

7. Capillary Action • - allows water to move through the roots of plants • - allows blood to flow through the tiny vessels in our bodies. • - explains how water moves into a paper towel when cleaning up a spill

9. How will this affect your boat? Adhesion Capillary Action However, because of capillary action, water will eventually move into the cardboard – hopefully very slowly!! • The water molecules will be attracted to the cardboard and ‘stick’ to it.

10. One last important bit of information!!! Find the boat’s center of gravity

11. NOT BALANCED – WILL SINK 100 Lbs C G NOT BALANCED – WILL SINK BALANCED 100 Lbs 100 Lbs 100 Lbs C G C G A BOAT in water is like a see saw BALANCED 100 Lbs C G

12. NOT BALANCED 50 lbs C G BALANCED NOT BALANCED 50 lbs 50 lbs 50 lbs C G C G A BOAT in water is like a see saw BALANCED 50 lbs C G