NZQA Expiring unit standard
21908 version 4
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Title
Demonstrate knowledge of basic mechanics for mechanical
engineering trades
Level
2
Credits
3
Purpose
People credited with this unit standard are able to demonstrate
knowledge of simple machines, friction in an engineering
environment, and Pascal’s Law.
Classification
Mechanical Engineering > Engineering Core Skills
Available grade
Achieved
Explanatory notes
1
Reference
The International System of Units (SI), 8th edition (France: Bureau International des
Poids et Mesures, 2006). Available at
http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf.
2
Assessment information
–Formulae shall be supplied.
–Use of calculator is permitted.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of simple machines.
Evidence requirements
1.1
Simple machines are identified and described according to mechanical
engineering practice.
Range
1.2
simple machines – first, second, and third order levers; wedge,
screw; pulley; wheel and axle.
Calculations involving length, forces, moments, torque, work, and power are
performed for simple machines.
Range
Competenz
SSB Code 101571
simple machines – lever; wedge, screw; pulley; wheel and axle;
evidence of calculations for three simple machines is required.
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
1.3
21908 version 4
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Calculations involving symmetrical triangular forces are performed.
Range
evidence of a minimum of three calculations is required.
Outcome 2
Demonstrate knowledge of friction in an engineering environment.
Evidence requirements
2.1
The nature of friction is explained with reference to applied forces and the
coefficient of friction.
2.2
Static, sliding, and rolling friction are distinguished.
2.3
Advantages and disadvantages of friction are stated.
Range
2.4
evidence of two advantages and one disadvantage is required.
Methods to reduce friction are stated.
Range
evidence of two methods that are incorporated into the design of a
machine and two methods that are under operator control is required.
Outcome 3
Demonstrate knowledge of Pascal’s Law.
Evidence requirements
3.1
Pascal’s Law is explained and an example of its application in mechanical
engineering stated.
3.2
Calculations involving hydrostatic pressure and piston forces in compressed
fluid situations are performed.
Range
evidence of a minimum of two different calculations is required.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
22 September 2005
31 December 2011
Revision
2
12 January 2006
31 December 2016
Review
3
17 November 2011
31 December 2020
Review
4
18 February 2016
31 December 2020
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
21908 version 4
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Consent and Moderation Requirements (CMR) reference
0013
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Competenz
SSB Code 101571
 New Zealand Qualifications Authority 2016