Skip to content Skip to navigation Skip to collection information

Connexions

You are here: Home » Content » Technology Grade 9 » Mechanisms and motion

Navigation

Lenses

What is a lens?

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

This content is ...

In these lenses

  • GETSenPhaseTech display tagshide tags

    This module and collection are included inLens: Siyavula: Technology (Gr. 7-9)
    By: Siyavula

    Module Review Status: In Review
    Collection Review Status: In Review

    Click the "GETSenPhaseTech" link to see all content selected in this lens.

    Click the tag icon tag icon to display tags associated with this content.

Recently Viewed

This feature requires Javascript to be enabled.

Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.
Download
x

Download collection as:

  • EPUB (what's this?)

    What is an EPUB file?

    EPUB is an electronic book format that can be read on a variety of mobile devices.

    Downloading to a reading device

    For detailed instructions on how to download this content's EPUB to your specific device, click the "(what's this?)" link.

  • More downloads ...

Download module as:

  • PDF
  • EPUB (what's this?)

    What is an EPUB file?

    EPUB is an electronic book format that can be read on a variety of mobile devices.

    Downloading to a reading device

    For detailed instructions on how to download this content's EPUB to your specific device, click the "(what's this?)" link.

  • More downloads ...
Reuse / Edit
x

Collection:

Module:

Add to a lens
x

Add collection to:

Add module to:

Add to Favorites
x

Add collection to:

Add module to:

 

Mechanisms and motion

Module by: Siyavula Uploaders. E-mail the author

TECHNOLOGY

Grade 9

MECHANISMS AND MOTION

Module 1

MECHANISMS AND MOTION

Introduction

What is a mechanism?

  • In our everyday life we are surrounded by mechanisms. They help make our life easier in many ways. Most of the mechanisms you use are so familiar that you never think about them. Simple things like door handles, light switches, parts of a bicycle and a car are only a few examples. In the past, in old machines such as steam engines, the mechanisms were easy to see. Today they are hidden behind panels and covers. Mechanisms allow us to do simple things like switching on lights, running a bath and peddling up the hill easily on a bicycle. You will discover the uses of different mechanisms, as we look at them closer in this module.

Activity 1

  • Make a list of items that you think are examples of mechanisms? Sketches and pictures of these items can also be included.
Table 1
         
  LO 1.2      
         

Mechanisms and Motion

  • Mechanisms can be used to change the speed, direction or force required to do something. Mechanisms may be able to help you but they cannot do it on their own. They need energy and someone or something to operate them. The energy that is used by a machine is called the input. The result of this energy input is called the output. A mechanism such as a bicycle can be explained with the diagram below.
Figure 1
Figure 1 (Picture 1.png)

Activity 2

  • Explain the advantages of sprockets and chains used in bicycles.

Figure 2
Figure 2 (Picture 2.png)
Table 2
         
  LO 2.3      
         
  • Mechanisms are concerned with motion. There are four main types of motion. These can be illustrated by means of human body movements.

Figure 3
Figure 3 (Picture 3.png)

Activity 3

  • Name the type of motion illustrated by the products. Use arrows to indicate the direction of the motion.Product
    Figure 4
    Figure 4 (Picture 4.png)
    Type of motion _________________Product
    Figure 5
    Figure 5 (Picture 5.png)
    Type of motion ___________________Product
    Figure 6
    Figure 6 (Picture 6.png)
    Type of motion ______________________Product
    Figure 7
    Figure 7 (Picture 7.png)
    Type of motion ________________
Table 3
         
  LO 2.3      
         

Types of mechanisms

Mechanisms are used in machinery. There are five types of mechanism:

  1. Levers enable forces to be applied at precise points.
  2. Pulleys change the direction and speed of a movement, and allow the transmission of power.
  3. Gears transmit rotary motion and force.
  4. Cams and cranks convert uniform input motion to non-uniform output motion.
  5. Screws allow rotary motion to transmit a linear force.

Activity 4

  • Answer the following questions based on the pictures A – F.

Figure 8
Figure 8 (Picture 8.png)

  1. 4.1. Name the mechanism in each of A - F.
  2. 4.2. Suggest a use for mechanism A.

  1. 4.1. In B, Axle 1 rotates at 10 rpm. How fast will axle 2 rotate?

  1. 4.1. To what use may mechanism C be put?

  1. 4.1. In D, if W rotates clockwise, how can you make V rotate anticlockwise?

  1. 4.1. Sketch a toy that could use mechanism F.
Table 4
         
  LO 2.3      
         

Assessment

Table 5
Learning outcomes(LOs)
 
LO 1
TECHNOLOGICAL PROCESSES AND SKILLSThe learner will be able to apply technological processes and skills ethically and responsibly using appropriate information and communication technology.
Assessment standards(ASs)
 
We know this when the learner:
investigates:1.2 analyses existing products relevant to an identified problem, need or opportunity based on:
  • safety;
  • suitability of materials;
  • fitness for purpose;
  • cost;
  • manufacturing method;
LO 2
TECHNOLOGICAL KNOWLEDGE AND UNDERSTANDINGThe learner will be able to understand and apply relevant technological knowledge ethically and responsibly.
We know this when the learner:
systems and control:2.3 demonstrates knowledge and understanding of interacting mechanical systems and sub-systems by practical analysis and represents them using system diagrams:
  • gear systems;
  • belt drive pulley systems with more than one stage;
  • mechanical control mechanism (e.g. ratchet and pawl, cleats);
  • pneumatic or hydraulic systems that use restrictors;
  • one-way valves;
  • systems where mechanical, electrical or pneumatic or hydraulic systems are combined;

Memorandum

ACTIVITY 1

  • Learners could list any product that they regard as a mechanism. The aim of the activity is to help the learners to become aware of how many products actually are mechanisms. Discuss their examples in the classroom.

ACTIVITY 2

2.1 Greater forces can be transferred

2.2 Chains do not slip/slide

2.3 Chains can be unlinked to facilitate removal

ACTIVITY 3

  • Door handle Oscillating (handle) and backwards and forwards-movement (reciprocating)
  • Tap Rotating movement
  • Air pump Oscillating
  • Pair of scissors Oscillating

ACTIVITY 4

  1. 4.1. A – Crank(-handle)

B – Gears

C – Propeller/screw

D – Pulley

E – Linkage/linking

F – Cam

  1. 4.1. Tricycle
  2. 4.2. Three times slower (15/5 = 3)
  3. 4.3. Store air-tight/Keep things tightly stored
  4. 4.4. Twist the rubber ring to form an 8.
  5. 4.5. Any cam-driven toy

Collection Navigation

Content actions

Download:

Collection as:

EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Module as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Add:

Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

Reuse / Edit:

Reuse or edit collection (?)

Check out and edit

If you have permission to edit this content, using the "Reuse / Edit" action will allow you to check the content out into your Personal Workspace or a shared Workgroup and then make your edits.

Derive a copy

If you don't have permission to edit the content, you can still use "Reuse / Edit" to adapt the content by creating a derived copy of it and then editing and publishing the copy.

| Reuse or edit module (?)

Check out and edit

If you have permission to edit this content, using the "Reuse / Edit" action will allow you to check the content out into your Personal Workspace or a shared Workgroup and then make your edits.

Derive a copy

If you don't have permission to edit the content, you can still use "Reuse / Edit" to adapt the content by creating a derived copy of it and then editing and publishing the copy.