Design & Technology: Product Design - 9252 OxfordAQA

Mechanical Devices

Muhtasari

Pick up a pair of nail clippers. Your thumb pushes down with a force you could apply all day, and at the other end two blades cut through a material that would blunt a kitchen knife. Nothing in the clippers generates any force at all. Every newton at the blades came from your thumb, and the clippers simply rearranged it, trading a long movement for a short one and a small force for a large one.

That trade is what mechanical devices do, and it is the whole of this lesson. You will learn the functions of mechanical devices that produce linear, rotary, reciprocating and oscillating movements, and how they change the magnitude and direction of force. You will meet levers of the first, second and third classes, linkages including bell cranks and push and pull arrangements, and rotary systems: cams and followers, simple gear trains, and pulleys and belts. You will calculate mechanical advantage, gear ratios and output speeds, and you will choose between three ways of doing the same job on a real product. This is core technical principles content, examined in Section A of Paper 1, where it supplied question 8 of the specimen paper.

Malengo

  1. The functions of mechanical devices to produce linear, rotary, reciprocating and oscillating movements.
  2. Changing magnitude and direction of force
  3. Levers:
  4. levers, first, second and third classes.
  5. Linkages:
  6. bell cranks
  7. push/pull.
  8. Rotary systems:
  9. cams and followers
  10. simple gear trains
  11. pulleys and belts.

Ramani ya mawazo

Mada hii imechorwa ili uone jinsi mawazo yanavyounganika.

Fungua ramani ya mawazo kwenye programu

Maelezo ya Somo

There is one idea underneath every mechanism in this topic. A mechanism cannot make energy. What it can do is exchange force for distance: if the output force is larger than the input force, the output must move a shorter distance, and if the output moves further or faster, it must do so with a smaller force. A long spanner turns a tight nut because your hand travels a long way round while the nut turns a little. A bicycle in a low gear climbs a hill because your feet turn many times for each turn of the wheel.

Dokezo Kamili la Somo Linapatikana kwenye Programu ya Green Bridge

Pata programu ya Green Bridge CBT kwenye simu au kompyuta yako kwa maktaba kamili ya IGCSE: mitihani ya miaka iliyopita, miongozo ya usahihishaji, ramani za mawazo, kadi za marudio na masomo ya sauti.

Maelezo kamili ya masomo yenye michoro
Msaidizi wa kujifunza wa AI
Mitihani ya majaribio yenye muda, husahihishwa mara umalizapo
Pakua programu ya simu Pakua programu ya kompyuta
Inapatikana kwa Android, Windows, macOS, na Linux Programu ya iOS inakuja hivi karibuni

Tathmini ya Somo

Hongera kwa kukamilisha somo la Mechanical Devices. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.

Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.

Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.

  1. A windscreen wiper blade moves backwards and forwards along an arc. This motion is described as A. linear. B. oscillating. C. reciprocating. D. rotary. Answer: B
  2. In which class of lever is the load always between the fulcrum and the effort? A. First class B. Second class C. Third class D. All classes Answer: B
  3. A driver gear of 12 teeth meshes with a driven gear of 36 teeth. The driver turns at 600 revolutions per minute. What is the output speed? A. 100 revolutions per minute B. 200 revolutions per minute C. 1,800 revolutions per minute D. 3,600 revolutions per minute Answer: B
  4. Which cam gives the follower a period of dwell in every revolution? A. An eccentric cam B. A pear cam C. A snail cam D. No cam can Answer: B
  5. An idler gear is added between a driver and a driven gear. What is its effect? A. It doubles the output speed B. It halves the output torque C. It reverses the direction of the driven gear without changing the ratio D. It has no effect at all Answer: C

Fanyia kazi maswali haya kwenye programu

Fanyia kazi maswali haya kwenye programu

Vitabu Vinavyopendekezwa

OxfordAQA International GCSE Design and Technology: Product Design (9252)
OxfordAQA International GCSE Design and Technology: Product Design (9252)
Manukuu: Student Book
Mchapishaji: Oxford University Press
Mwaka: 2024
ISBN: 978-1-382-05263-4
Maelezo: The endorsed student book for the 9252 specification, published for first teaching in 2023 and first assessment in 2025. Covers the core technical, specialist technical and designing and making principles, with practice questions in the paper's own shapes and guidance on the design and make task.
Making It
Making It
Manukuu: Manufacturing Techniques for Product Design, third edition
Mchapishaji: Laurence King Publishing
Mwaka: 2019
ISBN: 978-1-78627-327-7
Maelezo: Over 120 manufacturing processes, each shown on a real product with photographs of the tooling and a note on its environmental cost. The fastest way to understand why a process suits one production volume and not another, which is the judgement Section B of the paper keeps asking for.
The Design of Everyday Things
The Design of Everyday Things
Manukuu: Revised and expanded edition
Mchapishaji: Basic Books
Mwaka: 2013
ISBN: 978-0-465-05065-9
Maelezo: Why some doors are pushed when they should be pulled. Norman's account of affordances, signifiers, feedback and error is the clearest available grounding for the ergonomics and user centred design parts of the course, and it gives you the vocabulary to say precisely what is wrong with a product rather than that you do not like it.

Fanya Mazoezi ya Maswali ya Majaribio

Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Mechanical Devices? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.

Pakua Programu Kwenye Google Playstore

Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.

Green Bridge CBT Mobile App
Msaidizi wa Gumzo wa Kujifunza wa AI Uliobinafsishwa
Maswali ya mtihani zaidi ya 200,000 ya IGCSE, JAMB, WAEC na NECO
Zaidi ya Madaftari ya Masomo 1200
Msaada Nje ya Mtandao - Jifunze Wakati Wowote, Popote Pale
Ratiba ya Daraja la Kijani
Muhtasari wa Fasihi na Maswali Yanayoweza Kutokea
Fuata Utendaji na Maendeleo Yako
Maelezo ya Kina kwa Kujifunza kwa Kina