-SQA- SCOTTISH QUALIFICATIONS AUTHORITY HIGHER NATIONAL UNIT SPECIFICATION GENERAL INFORMATION -Unit Number- 3471286 -Superclass- -Title- RC ROTATIONAL MECHANICS ----------------------------------------- -DESCRIPTION- GENERAL COMPETENCE FOR UNIT: Applying the concept of centripetal force and Newton s Laws of Motion, predicting the behaviour of SHM systems, and performing experiments relating to rotational mechanics. S 1. apply the concept of centripetal force; 2. apply Newton s Laws of Motion to the rotation of a rigid body; 3. predict the behaviour of SHM systems; 4. perform, analyse and report on an experiment relating to rotational mechanics. CREDIT VALUE: 0.5 HN Credit ACCESS STATEMENT: NC Stage 2 (3171111) Mechanics and appropriate NC Mathematic modules, or equivalent. ----------------------------------------- For further information contact: Committee and Administration Unit, SQA, Hanover House, 24 Douglas Street, Glasgow G2 7NQ. Additional copies of this unit may be purchased from SQA (Sales and Despatch section). At the time of publication, the cost is 1.50 (minimum order ( 5.00).
HIGHER NATIONAL UNIT SPECIFICATION STATEMENT OF STANDARDS UNIT NUMBER: 3471286 UNIT TITLE: ROTATIONAL MECHANICS Acceptable performance in this unit will be the satisfactory achievement of the standards set out in this part of the specification. All sections of the statement of standards are mandatory and cannot be altered without reference to SQA. 1. APPLY THE CONCEPT OF CENTRIPETAL FORCE The calculation of centripetal force is correct for simple systems in physics and engineering. The law of Gravitation is used to estimate the motion of planets and satellites accurately. Centripetal force: v = rω ; 2 F = m ω r Law of Gravitation: F = G M M 2 r 1 2 Written evidence of the ability to apply the concept of centripetal force and to use each equation given in the range statement. 2. APPLY NEWTON S LAWS OF MOTION TO THE ROTATION OF A RIGID BODY The calculation of resultant torque on a rigid body is correct. 2
The use of equations of motion for a rigid body rotating about a fixed axis at constant angular acceleration is correct with respect to the prediction of the angular velocity and angular displacement at a given time. The range statement for this outcome is fully expressed within the performance criteria. Written evidence of the calculation of torque and of the use of the equations of motion. 3. PREDICT THE BEHAVIOUR OF SHM SYSTEMS (c) The identification of bodies oscillating with SHM from their equations of motion is correct. The description of the relations between displacement, velocity and acceleration are correct for a free simple harmonic oscillator with no damping present. The prediction of the effect of damping on a body oscillating with SHM is accurate. The range for this outcome is fully expressed within the performance criteria. Written evidence of the ability to apply the concepts of SHM behaviour to simple SHM systems. 3
4. PERFORM, ANALYSE AND REPORT ON AN EXPERIMENT RELATING TO ROTATIONAL MECHANICS (c) (d) (e) (f) (g) The setting up of the equipment is in accordance with the given specification. The experimental procedures carried out are correct and safe. The recording of the procedures, relevant observations and measurements is complete and accurate with numerical uncertainties where appropriate. The presented data is in an appropriate format. The identification of valid experimental and instrumental errors is correct. The calculation and presentation of the overall uncertainties is correct and in the appropriate format. The conclusions/analyses are valid within the limits of experimental uncertainties. The range statement for this outcome is fully expressed within the performance criteria. A checklist of observation in relation to Performance Criteria and. Written, dictated or transcribed evidence recording observations, measurements errors and uncertainties. Evidence in the form of a report detailing the conclusions and analyses. MERIT To achieve a pass in this unit, a candidate must meet the standards set out in the outcomes, performance criteria, range statements and evidence requirements. To achieve a pass with merit in this unit, a candidate must demonstrate a superior or more sophisticated level of performance. This would be demonstrated by two of the following: - the correct calculation of centripetal force for more complex systems. - the correct completion of more complex predictions of angular velocity and angular displacement for a rigid body. - the production of a practical report with an in-depth analysis and well presented conclusions. ----------------------------------------- 4
ASSESSMENT In order to achieve this unit, candidates are required to present sufficient evidence that they have met all the performance criteria for each outcome within the range specified. Details of these requirements are given for each outcome. The assessment instruments used should follow the general guidance offered by the SQA assessment model and an integrative approach to assessment is encouraged. (See references at the end of support notes). Accurate records should be made of the assessment instruments used showing how evidence is generated for each outcome and giving marking schemes and/or checklists, etc. Records of candidates achievements should be kept. These records will be available for external verification. SPECIAL NEEDS Proposals to modify outcomes, range statements or agreed assessment arrangements should be discussed in the first place with the external verifier. Copyright SQA 1996 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 5
HIGHER NATIONAL UNIT SPECIFICATION SUPPORT NOTES UNIT NUMBER: 3471286 UNIT TITLE: ROTATIONAL MECHANICS SUPPORT NOTES: This part of the unit specification is offered as guidance. None of the sections of the support notes is mandatory. NOTIONAL DESIGN LENGTH: SQA allocates a notional design length to a unit on the basis of time estimated for achievement of the stated standards by a candidate whose starting point is as described in the access statement. The notional design length for this unit is 20 hours. The use of notional design length for programme design and timetabling is advisory only. PURPOSE This unit would normally be used as part of general HNC awards in Science, or in subjects where a specific Physics content is required. CONTENT/CONTEXT Rotational variables: θ, ω, f, T, υ, a. 2 3 Relation between distance and period for satellite ( T α d ) Torque; r F sin θ ; rf ; r F (alternative); Iα (simple cases for I); Equation of motion &&x + k m x = 0 Simple systems such as mass on spring Qualitative relations between x, v and a (eg by graph) Damping - 3 cases (oscillatory, critical, overdamped) 6
REFERENCES 1. Guide to unit writing. 2. For a fuller discussion on assessment issues, please refer to SQA s Guide to Assessment. 3. Information for centres on SQA s operating procedures is contained in SQA s Guide to Procedures. 4. For details of other SQA publications, please consult SQA s publications list. Copyright SQA 1996 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 7