NPS Kid's Pages

DARBY DUCK AND THE AQUATIC CRUSADERS

Ever wonder how things can move in the water?
Try this!

Materials:

• large, clean bowl of water
• thin cardboard (index card or notebook cover)
• scissors
• liquid dish detergent
• pencil

Procedure:

1. Draw a triangle on the thin cardboard

2. Cut out the triangle-shaped boat and float it on the water near the edge of the bowl.

3. Put a drop of liquid detergent on your fnger.

4. Gently touch the water behind the boat with your soap covered finger. What happens?

5. If you want to do this again, you need to get new water that has no detergent in it.

How it Works:

The detergent on your finger weakens the surface tension of the water behind the boat. There is still strong surface tension in the front of the boat so the boat is pulled forward.

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Darby's Front Page

[CRITTER SCOPE][SURFACE TENSION][SHAKE IT UP!][SPEEDBOATS] [EXPLODING COLORS][SINK OR SWIM][WATER OFF HIS BACK]

OWOW Homepage || NPS Homepage EPA HOMEPAGE | WATER HOME | SEARCH | COMMENTS  Environmental Protection Agency's Office of Wetlands, Oceans, & Watersheds  Revised October 15, 1997  url: http://www.epa.gov/owow/nps/kids/SPBOATS.HTM