Timbers And Boards
Gbogbo ọrọ náà
Wood is one of the oldest engineering materials and still one of the most useful. It is a renewable, workable, surprisingly strong material that comes straight from a living tree, and the way a tree grows leaves clues in the wood - the grain, the rings, the knots - that a designer learns to read. The first and most important split is between softwoods from fast-growing evergreen trees and hardwoods from slower broadleaved trees, a classification based on the type of tree, not simply on how hard the wood feels.
This note covers the 0445 Materials-option timber objectives: classifying natural timbers, their stock forms, properties, environmental impact and uses; the named softwoods (cedar, pine, redwood, spruce) and hardwoods (oak, mahogany, meranti, jelutong); the family of manufactured boards including plywood, chipboard and MDF; and a clear-eyed comparison of when a manufactured board beats solid timber and when it does not.
Ebumnobi
- demonstrate knowledge of natural timbers and understand their classification, stock forms, properties, environmental impact and uses
- demonstrate knowledge of softwood timbers, for example: - cedar - pine - redwood - spruce - local equivalents
- demonstrate knowledge of hardwood timbers, for example: - oak - mahogany - meranti - jelutong - local equivalents
- demonstrate knowledge of manufactured boards, for example: - plywood - chipboard - fibre-based boards including medium density fibreboard (MDF) - local equivalents
- understand the advantages and disadvantages of working with manufactured boards compared with natural timbers.
Nkuzi Olu
Gee ntị na nkuzi a na ngwa
Maapụ uche
E seela isiokwu a ka ị hụ otu echiche si ejikọta.
Mepee maapụ uche na ngwa
Kaadị ncheta
Omume ncheta ngwa ngwa n'ihe a na-anwale n'isiokwu a.
Mee omume kaadị ndị a na ngwa
Akwụkwọ Ọmụmụ
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.
Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na Timbers And Boards. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- Which feature defines a hardwood? A. The wood is always physically hard B. It comes from a deciduous broadleaved tree C. It is always darker than a softwood D. It cannot be used for furniture Answer: B
- Which softwood is naturally durable and most suitable for outdoor cladding without heavy treatment? A. Spruce B. Pine C. Cedar D. Jelutong Answer: C
- Why does plywood have an odd number of veneers? A. To make it cheaper B. So the grain of the outer veneers runs the same way and the panel stays balanced and flat C. To allow it to be bent into curves D. So it can be used outdoors Answer: B
- Which is a correct disadvantage of MDF compared with solid timber? A. It cannot be painted B. It is more expensive than oak C. It swells and is weakened if it gets wet, and its dust is a health hazard D. It is too strong to machine Answer: C
- Why are brass or stainless steel screws preferred to ordinary steel screws when working with oak? A. Oak is too soft for steel screws B. The tannin in oak corrodes steel and causes blue-black staining C. Steel screws are more expensive D. Oak cannot be drilled Answer: B
Rue ajuju ndi a n'ime ngwa ahu
Rue ajuju ndi a n'ime ngwa ahu
Akwụkwọ A Na-atụ Aro
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara Timbers And Boards? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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