Hydro Power with Water Wheels

The Hydro Power with Water Wheels activity was designed as part of Designing Green with Olin College Engineering Discovery! It is targeted at elementary school children.

Goal

Students will understand how a water wheel works, the types of energy involved, and how this energy can be harnessed to perform some other task.

Materials

The following materials are necessary:

  • Pictures of old fashioned watermills from outside and inside
  • Shirt cardboard cut into three-inch circles
  • Straws
  • One-ounce paper cups
  • Basin of water
  • Pitcher
  • Pencils
  • Stapler

Preparation for Activity

  1. Fill basin and pitchers with water (1 for each pair of students)
  2. Lay out cardboard, straws, and cups for each student

Discussion

  1. What is the one resource every human being must have to live?
    1. Water
  2. Where is moving water found in nature?
    1. Rivers
    2. tides
  3. What is it called when water is used for energy? How has it been used?
    1. Hydropower
    2. Used to run saws and ground grain
    3. Dams - water released through sluice, moving turbines to generate electricity
  4. Who knows how a water wheel works?
    1. Wheel turns when rushing water falls into buckets or paddles attached to the wheel
    2. Large wheel connected by a shaft to gears, mill stones, saws, etc.
    3. Show pictures of water wheels!
  5. Let's talk about the transfer of energy happening here
    1. What are some types of energy that you guys know about?
      1. Potential, kinetic, electric, static, ...
    2. Right, so when the water starts really high like in a waterfall, what type of energy does it have?
      1. Potential - be sure they can explain this (has somewhere to fall)
    3. What type of energy does the water have as it falls?
      1. Kinetic - it is in motion
    4. What happens to this kinetic energy? How it is used?
      1. Electric, kinetic (for mechanical systems), etc.
  6. Now we are going to let you guys build your own water wheels

Protocol

  1. Give each child a cardboard circle, a straw, and three paper cups
  2. Children use a pencil to punch a hole in the middle of the circle.
  3. Then they can place the straw in the hole.
  4. Have them staple three cups at even intervals at the outside edge of the cardboard circle.
  5. Have children work in pairs to demonstrate how water moves a water wheel. One child holds two ends of the straw over the basin as the other child slowly pours water from the pitcher into the cups of the waterwheel.
  6. Let them play around with different design ideas!
    1. Change number of cups?
    2. Change depth of cups?
    3. Change spacing of cups?

Conclusions

  1. Overview how a water wheel works
  2. Overview transfer of energy
  3. What sorts of attachments could be added to a water wheel to make a machine that does some work?