Grade Level: 6th - 8th; Type: Physical Science
Students will create an uphill flow of water by using a siphon.
- What forces are acting on the liquids?
- How is a vacuum created?
What goes up must come down. You wouldn’t think this would help us explain how water can flow uphill. To drink a glass of water you must raise the glass above your mouth. The water is pulled down by gravity into your mouth. What’s another way to drink a glass of water without lifting the glass? Use a straw. A straw creates a vacuum, or negative pressure, so water is pulled up the straw. We can use these principles to create an uphill flow of water.
- 1+ gallon bucket (2)
- Clear tubing approximately 3 feet in length (can be found in a science lab or purchased at a hardware store)
- Place one bucket on a stool and the other bucket on the ground.
- Fill the top bucket with water.
- Place one end of the tube in the top bucket, submerged in the water at the base.
- Create a vacuum on the opposite end by suctioning the water up the tube like drinking from a straw.
- Once water gets to the end of the tube immediately place it in the bottom bucket.
- What happens? In what direction does the water travel?
- Now reverse making the water flow up into the top bucket.
- Fill the bottom bucket with water. The top bucket should be empty.
- Place one end of the tubing in the bottom bucket and create a vacuum.
- Once the water reaches the other end of the tube immediately place it in the top bucket, near the base.
- What happens? Does the water travel in the same direction?
Terms/Concepts: Atmospheric pressure; Vacuum; Siphon