Home > Subjects > Physics > Level 3 > 3.4 Mechanical systems > Achievement criteria
- Subject: Physics
- AS: AS90521
- Level: 3
- Credits: 6
- External
Physics 3.4 Demonstrate understanding of mechanical systems
Achievement criteria
The level of performance that you will gain will be determined by both the complexity of the situation and problem-solving process of aspects of mechanical systems.
Minor errors (computational or transcription) will not be penalised if the process used to determine the solution is clearly indicated and is valid.
Achievement
Make sure you can:
- Identify or describe aspects of phenomena, concepts, or principles.
- Solve straightforward problems that involve a single-step process.
- Recognise correct concept/phenomenon/principle and give a simple descriptive answer in both written and diagrammatic form, for example:
- how the simple harmonic motion (SHM) restoring force is always directed towards an equilibrium position
- the natural period of a pendulum is related only to its length and the gravitational acceleration
- how energy loss reduces amplitude of an SHM but has no effect on its period
- the nature of the centripetal force that causes orbital motion around planets
- how mass distribution about the axis affects rotational inertia
- how angular momentum is conserved when a diver rotates in the air.
- Recognise the correct concept and apply reasonable mathematical skills, for example:
- the frequency of an SHM
- the maximum acceleration of a pendulum relates to the amplitude of its motion
- the angular momentum of a rotating body relates to the angular speed.
Achievement with Merit
Make sure you can:
- Meet criteria for Achievement.
- Give accurate explanations in terms of phenomena, concepts, principles, and/or relationships.
- Solve problems that may involve using a complex formula or rearrangement or some deduction as to the relevant concept or principle.
- Use physics terminology to demonstrate a higher level of understanding of physics concepts, for example:
- connection between circular motion and gravitation
- relationship between free-fall and weightlessness
- difference between gravitational force and acceleration due to gravity
- difference between circular motion and SHM.
Achievement with Excellence
Make sure you can:
- Meet criteria for Merit.
- Give concise and accurate explanations that show clear understanding in terms of phenomena, concepts, principles, and/or relationships. Your answers will typically have minimal irrelevancies. In other words, you cannot include any explanations that are not relevant. Do not guess!
- Solve complex problems that will involve more than one process and concept.
- Show numerical accuracy and correct rounding, and use SI units in answers.
- Understand fully the physical situations and questions asked for that concept, that is, present a multi-step mathematical solution that links to the required physics concept/principle, and successfully apply it to the context given.
