Science experiments you can do at home - ()

Author: Zhou Shizhong
Publisher:
Publish Date: 2006-06-01
Features: Centrifugal Pump
Jiajia went to the suburbs for a play and saw a pump "gurgling" water out. She thought it was fun but didn't know what kind of machine it was. When she got home, she asked her dad. Dad said, "This is a centrifugal pump, specifically designed for pumping water."
"Centrifugal pump?" Jiajia still didn't understand. Dad said, "Then I'll teach you how to make a simple centrifugal pump to play with." He asked Jiajia to fill a flexible rubber hose with water, insert it into a large bucket full of water, and hang the other end outside the bucket. Once the water started flowing out of the hose, Dad said, "Now, hold the hose at the bucket's opening and swing the end that's spraying water. See what happens?"
Jiajia did as her dad said and swung the hose. She saw the water being pumped out of the bucket and excitedly said, "Our pump is starting to pump water!"
"This is a simple centrifugal pump," Dad said.
Kids, do you know the scientific principle behind this?
Science Corner: When swinging the hose, it's important to rotate it horizontally so that the water in the bucket can be lifted. When we spin an umbrella, the rainwater on it spins away from the umbrella—this is the result of centrifugal force. Similarly, when swinging the hose, a centrifugal force is generated in the hose, causing the water to be flung out. Under the action of atmospheric pressure, the water in the bucket quickly fills the empty hose, so the water in the bucket is continuously pumped out.