Planning a school fair, looking for some fundraising activities or new ways to keep your young people entertained over the summer? Gratnells Learning Rooms has gone carnival crazy to support good causes and engage the community through fun games and STEM activities.
You will be able to:
- Experiment and evaluate a range of methods to propel a duck down a racing channel
You will need:
- 6 x Jumbo Gratnells (F3) tray
- 2 x Extra Deep Gratnells (F25) tray
- 2 x 4m lengths square white guttering
- 4 x White square guttering stop-ends
- 2-3 x Large buckets of water
- 2 x Rubber Duck – or other floating items of your choice
- 2 x Squirt bottle – or other methods of propelling the ducks
- Sufficient water to two-thirds fill the guttering lengths
- 1 x Mixed pack of multi-coloured insulating tape (for decoration/distance markers)
- 8-12 x Colourful pipe cleaners (for decoration/distance markers)
- 2 x Drinking straws (for decoration/distance markers)
- 1 x Instruction sheet printable
- 1 x Stopwatch (optional)
- 6-8 x Cups of water beads (optional)
- 2-10 x Gratnells mini tray, or other items suitable for levelling the guttering e.g. small wooden blocks
- A selection of small prizes of your choosing
- Attach the stop-ends to the guttering.
- Decorate the guttering with stripes of insulating tape at regular intervals along its length.
- Cut the drinking straws in to 2-3cm pieces and tape each piece, in pairs on opposite sides, vertically on the outside of the guttering. Slot the pipe cleaners into the straw pieces to create small hoops at regular intervals along the length of each piece of guttering.
- Place one upturned jumbo tray at each end of the guttering lengths and one in the centre.
- Two-thirds fill the guttering with water and add the water beads (optional), use the mini trays to level the guttering if needed.
- Print and laminate (optional) the instruction sheet.
What to do:
- Fastest duck wins a prize.
- Find a person to race against.
- Fill the squirt bottles with water.
- Choose one duck each and place them at the start ends of the guttering.
- Do a count down, 3, 2, 1, GO! Start the stopwatch (and video recorder if you are filming your race).
- Squirt water on the ducks to ‘push’ them towards the finish end of the guttering.
- Stop the stopwatch when the first duck hits the finish end of the guttering. Note down the winning time.
- The fastest duck wins a prize.
- Modify your method or squirt bottle and have another race, does your modification improve the speed of your duck?
What is happening?
The squirt bottles have a narrow spout, when water flows from the main container into a narrower channel its speed, and therefore its kinetic energy, increases. The increased kinetic energy comes from the work done by your hands on the water to push it from the main container into the narrow spout. The kinetic energy of the water can be used as a force to move the duck forward. The kinetic energy of the water is converted into mechanical (movement) energy of the duck. The angle of the water stream and the distance between the spout and the duck will affect the duck’s speed and direction of travel, along with the amount of work done to expel the water from the squirt bottle.
The speed of the duck’s travel will also be influenced by its buoyancy and water resistance. The more hydrodynamic the duck, the lower the water resistance and the faster the duck will move.
Other things to try…
- Swap the ducks for some home-made boats. Consider water resistance and buoyancy of your boat design, along with something to ‘catch’ the water jet from the squirt bottle. Time every race and record the effect of your modifications. Change one variable at a time while keeping all of the others constant. For more details on boat design take a look at our Sailboats What’s In My Tray activity.
- Swap the squirt bottles for a fan, either manual fan or small battery-powered one. Does wind power or waterpower move the duck or boat at the greatest speed? Can you modify your boat design to harness the most wind power? e.g. via the addition of a sail. Time every race and record the effect of your modifications. Change one variable at a time while keeping all others constant.
- Share photographs and videos of your duck or boat races on social media using #WhatsInMyTray
Health & Safety
As with all Gratnells Learning Rooms What’s In My Tray activities, you should carry out your own risk assessment prior to undertaking any of the activities or demonstrations.