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UPCOT FARM
Worksheet 10
Audio Cassette References:
- Robert Clatworthy
- Steven Hayes
- Johnny Bray
Video Cassette References:
- Sequence 1
- Sequence 9
- Sequence 14
- Sequence 22
Teacher Notes - Upcot Farm
The questions in this section seem open and a key issue is: what is meant by 'best'?
The questions could lead to one or two of the following investigations, though these are clearly not exhaustive. They are generally within science and technology.Discussion can be introduced either very open endedly, or with the help of pictures of animal housing units such as those supplied.
A number of criteria could be established for the buildings, eg. 'it must keep them warm'; it must keep them dry'; 'it must not collapse under the weight of snow'; 'it must not wash-a-way/rust-a-way', etc. The approach then depends on whether the pupil is to work mostly within Science or Technology.
Animal Housing - Shape
What is the best shape for livestock housing to withstand snow?
Materials: stimulus photographs of different shaped barns, sheets of A4 card, sand (to simulate snow), two weights to hold the sides in (heavy books will do).
Activity: the card can be used to construct open-ended (literally) barns with a flat roof, a pitched roof or semi-cylindrical. The pouring of sand can be used to test to destruction
Animal Housing - Materials
What is the best material for a barn to keep animals warm?
Materials: photographs of sheds of different materials, pieces of building materials with different thermal conductivities, e.g. galvanised iron, PVC, wood.The task can be approached at a number of levels from simply feeling the materials through to setting up a container of hot water to simulate the animal, covering it with the material and seeing which cools quickest.
What is the best material to line a box to keep a lamb warm?
This can be approached in the same way as above but the materials will be different cloths, paper, packing materials (expanded polystyrene is interesting).
Building a Barn - Materials
The structure of most modern farm buildings is based on concrete and reinforced concrete. An enjoyable, but messy, simulation of concrete beams can be made using plaster of paris in a cardboard mould. Beams of about 20cm long and 3cm square (max) cross section can be used. The mixtures can be varied with different amounts of sand or other substances used to simulate concrete.String (under tension while the plaster dries) makes a substitute for steel if reinforced concrete is wanted.
Testing these beams to destruction can be tried. The beams should be supported at the ends and different weights suspended from the middle.These beams can be surprisingly strong so care should be taken that heavy weights are not likely to fall on small (or large) feet.
Building a Barn - Fixings
Most farm buildings are held together by steel fixings, usually nails.These fixings should be rustproof in some way.
For iron and steel to rust, both water and air are needed. This can be demonstrated by placing clean, dry steel nails into a number of containers (e.g. jam jars).To these are added:
- Jar 1 - nothing (keep it dry and covered)
- Jar 2 - boiled water, completely covering the nail (ideally with a layer of oil on top of the water to stop any oxygen dissolving in the water
- Jar 3 - a small amount of water partially covering the nail.
After a few days it will be clear that the nail in jar 3 rusts first.
Investigations can now be conducted into what will stop the nails rusting under the conditions of Jar 3. Paint and grease both work. Try a pair of galvanised nails, one of which has had the galvanising partially scraped off.