Knowledge of machines
Machines consist of fixed and moving parts that modify mechanical energy and transmit it in a more useful form. A simple machine — such as a lever, a pulley, or an inclined plane — alters the magnitude, direction, or both of these of an applied force.
Complex machines have internal energy systems (electric motors, steam engines, turbines, combustion engines, solar energy systems, nuclear systems) that combine with levers, inclined planes and screws to enable the machine to perform their intended functions.
Initially, students learn about simple machines such as levers, inclined planes and screws and how when combined with mechanical components they are able to achieve a mechanical advantage and motion. This should progress to students learning how to explain the functionality of complex machines using technical language, diagrams and symbols and to being able to evaluate such machines in terms of their energy efficiency in order to suggest ways of improving this.
| Level 6 | Level 7 | Level 8 | |
| Demonstrate understanding of basic concepts related to machines | Demonstrate understanding of advanced concepts related to machines | Demonstrate understandings of complex concepts related to machines |
| To support students to understanding basic concepts related to machines at level 6, teachers could do the following. Provide opportunity for students to explain the purpose of levers, inclined planes and screws. Provide opportunity for students to explain the purpose of a range of mechanical components within a range of machines. Guide students to explain the advantages and disadvantages of pneumatic and hydraulic systems. Guide students to understand how a range of machines provide mechanical advantage and motion. Guide students to discuss why particular levers, inclined planes and screws, and mechanical components were selected to ensure mechanical advantage and motion in across a range of machines. | To support students to understanding advanced concepts related to machines at level 7, teachers could do the following. Provide opportunity for students to explore efficiencies of machines ( block and tackle, chain block, pneumatic or hydraulic jack, and turntable) and explain their safe use.
Guide students to explain how mechanical components combine to provide the desired mechanical advantage, and relative motion between input and output in a range of machines. Guide students to discuss for a range of machines how mechanical advantage was obtained by combining mechanical components, the relative motion between input and output for the machines, and efficiency(s) obtained. Note: a machines efficiency is determined by the ratio of the energy delivered (or work done) by a machine to the energy needed (or work required) to operate it (that is, output energy/input energy). | To support students to understanding complex concepts related to machines at level 8, teachers could do the following. Guide students to explain how complex machines work, using technical language, diagrams and symbols as appropriate. Support students to discuss how components enable complex machines to achieve their functions. Support students to discuss the energy efficiency of complex machines and how this impacts on the requirements for the machine’s energy system. Provide opportunity for students to evaluate the energy efficiency of complex machines and determine possible ways of increasing their energy efficiency. |
| Students are able to do the following. Explain the purpose of levers, inclined planes and screws. Explain the purpose of a range of mechanical components. Explain the advantages and disadvantages of pneumatic and hydraulic systems. Explain how a machine provides the mechanical advantage and motion. Discuss why particular levers, inclined planes and screws, and mechanical components were selected to ensure the mechanical advantage and motion in machines. | Students are able to do the following. Describe the efficiencies of machines in relation to their safe application. Explain how mechanical components combine to provide the desired mechanical advantage, and relative motion between input and output in a range of machines. Discuss why mechanical components were combined to provide the mechanical advantage, relative motion between input and output, and efficiency desired in a range of machines. | Students are able to do the following. Explain how complex machines work, using technical language, diagrams and symbols as appropriate. Discuss how the components enable complex machines to achieve their functions. Discuss the energy efficiency of complex machines and how this impacts on the requirements for the machine’s energy system. Evaluate the energy efficiency of complex machines and justify possible ways of increasing their energy efficiency. |
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AS91062 Construction & Mechanical Technologies 1.25Demonstrate understanding of basic concepts related to machines Standards & Assessment |
AS91349 Construction & Mechanical Technologies 2.25Demonstrate understanding of advanced concepts related to machines Standards & Assessment |
AS91625 Construction & Mechanical Technologies 3.25Demonstrate understanding of advanced concepts related to machines Standards & Assessment |