Activity

Water wheel to lift a weight

Summary
Make a wheel that can be turned by water to raise a weight. Discuss traditional and sustainable uses of water wheels for food and power.
Science content
Biology: Indigenous People's sustainable use of Living Things (K, 2, 3)
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Physics: Simple and complex Machines (5)
Earth/Space: Sustainable practices, Interconnectedness (2, 5, 7)
Materials
  • tray (IKEA Trofast tray ideal)
  • 2 supports for rod e.g. U-shaped foam pipe insulation, cut to 5cm length
  • masking tape
  • pie plate
  • pencil to punch hole in pie plate
  • wooden rod ~3/8” diameter
  • additional foam piece to secure wheel on rod
  • scissors
  • string, length of table height
  • small pot and marble, or other weight to lift
  • 2L bottle of water
  • funnel (to pour water back into the bottle)
  • extra water (in 2L bottles or watering can) for lost water
  • cloths and mop for spills
Procedure

Lift an object from the floor to the table top, using the force of falling water on a water wheel.
One set-up per student pair or group of three ideal.

Cut out the flat centre of an aluminum pie plate (take care with cut aluminium plates - the edges are sharp). Using a pencil, punch a hole through the centre of the pie plate.
Wrap a small piece of foam around the wooden rod and tape it in place. Push the rod through the hole in the pie plate, enlarging the hole until the plate fits snugly on the foam around the rod. The plate should not turn easily at all.
Make cuts from the edge of the pie pan 2/3 of the way to the centre, in four places. Fold over the sides of each section to make a paddle wheel shape.

Tape U-shaped pieces of foam to the centre of each of the long sides of the tray.
Lay the wheel and axle (rod) over the foam supports on the tray. Test that it can turn without hitting the bottom of the tray. If necessary, fold over the outside edges of the pie plate.
Make sure one end of the rod protrudes over the edge of the tray more, then tape the string to this end of the rod. Cut the string off where it meets the floor, and tie on a pot and marble, or other small weight e.g. the scissors.

Students pour water from the 2L bottle onto the wheel. The weight of the water hitting the paddle blades generates a force with makes the blades move and the wheel turn. The turning wheel turns the rod (axle), which winds the string and pulls up the weight.
Once the water runs out, pour the tray of water back into the bottle for reuse.
Students can be challenged to control how they pour the water to make the weight raise slowly or faster.

A fish wheel turns in the moving water of a river and has attached netting to catch salmon.
Fish wheels are used to catch salmon during a run, either for food or for tagging (to track salmon populations).
https://www.youtube.com/watch?v=-l81d3R1-OY
https://www.youtube.com/watch?v=uPoKHOMlhZ0

In a traditional water mill, a water wheel turns grindstones to make flour:
https://www.youtube.com/watch?v=1L5Pt4BLeos

Hydroelectric power is made from a water wheel (called a turbine):
https://www.youtube.com/watch?v=OC8Lbyeyh-E

Notes

The cut foil is SHARP. Need to use something else for the wheel if students are going to make their own, or tape the cut edges.

Grades taught
Gr K
Gr 2
Gr 3
Gr 4
Gr 5