Target Audience
Key Stage 2
Link to the National Curriculum
Sc4 Physical Processes (Forces)
Statutory requirements Yr 5
Children should be taught to:
- “Identify the effects of air resistance, water resistance and friction, that act between different surfaces”
Non Statutory (Notes for Guidance) Yr5
Children should be taught:
- “that they might explore resistance in water by making and testing boats of different shapes”
Objective
- To enable the children to understand that friction occurs everywhere in relation to movement on land, water and in the air.
Preliminary Activity
- Preliminary work could take the form of research into the “First Boat” i.e. how man possibly invented the first boat.
- This also allows for creative writing / drawing where the children give their own cartoon version of how this invention might have occurred..
What you need
- A length of water guttering approx 30 inches ( 75 cms.)
- Two stop ends for the guttering.
- Two guttering supports unless the guttering is flat bottomed.
- Balsa wood shapes
- Paper clips
- Dress making pins
- Cotton
- Stop watch
- Recording sheets
What you do
- Watch the video clip re “Best Hull shape” from the website: practicalprimaryscience.co.uk
- Set up the guttering as seen in the video clip
- Fill the guttering ¾ full of water*
- Cut length of cotton for attaching to each shape and attach 3 paper clips
- Give children recording sheets and a stop watch to record time taken for each shape to travel the length of the water trough.
- When finished the water should be siphoned it off bit by bit to save unnecessary spillage.
Group / Class organisation
- Split the class into groups of 3 or 4*
- Tell the children to take turns with the stop watches.
- Insist that all measurements must be made under the same conditions to make it a fair test.
- Each shape can be timed three times and an average (mean taken)
- Results should be recorded on their individual recording sheets.
* Regarding additional adult help, much will depend on the maturity of
of the children and the previous experience they have had of
practical investigative work. Clearly, if the children, for various reasons,
are unable to work in this fashion, then the activity will be for one group
at a time, with the others doing associated activities.
How it works
- From this very practical exercise the children themselves will be able to see that less drag (friction) is created as each hull shape becomes more streamlined. With 5 sets of apparatus (guttering and balsa wood shapes) it is possible for all children in the class to undertake this investigation at the same time.
- This investigation allows the children to practice other skills, such as the use of a stop watch in a very meaningful way. It also allows for the practice of calculating average timings if each shape is repeated three times.
Follow Up work
- Once the most streamlined hull shape has been established, this can be further added to by changing other variables such as: the width to discover the best width shape, followed by depth to discover the proportion of each to each other*.
- Please note that only one variable can be changed for each investigation