Physics - Department of Education · These definitions are to be in sufficient detail that they will serve both as a blueprint, describing all ... and theories of Physics to physical

Physics

Course Code: PHY415114

External Assessment Specifications 2015-2018

Tasmanian Qualifications Authority Page 1 of 18

PURPOSE

The purpose of the External Assessment Specifications is to provide information about the external assessment that defines:

the external assessable aspects of the criterion standards of PHY415115 Physics

the externally assessed course areas

the nature and range of appropriate types of items1, and

the structure of the external assessment.

These definitions are to be in sufficient detail that they will serve both as a blueprint, describing all the elements required to develop the assessment, and as a basis for accountability.

The External Assessment Specifications are primarily written for use by the setters of the assessment.

Whenever a new external assessment is required, the assessment is to comply with these technical specifications. Assessments may differ from year to year within the framework and rules provided by these specifications.

INTRODUCTION

The external assessment for PHY415115 Physics consists of a written examination. The external assessment is designed to assess the standard of achievement of skills, knowledge and understanding of candidates in targeted course areas. Understanding is assessed by the degree to which both knowledge of principles and theories of physics, and also skills, are applied to a range of item types2 in theoretical or approximated real-world scenarios.

The course document PHY415115 Physics is the document used for the development of the examination.

1 In these specifications, the term item is defined as an individual task to be undertaken by candidates. The task may be divided into several parts.

2 Definitions of relevant assessment item types are given in Attachment 1.

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OVERALL CONDITIONS

The time/date of the examination are set annually by the Office of TASC

The examination has a duration of three (3) hours

An additional fifteen (15) minutes reading time is given

The TASC External Assessment Rule applies to this external assessment. Details of the rule are published on the TASC website

TASC appoints appropriate persons to set and mark assessments.

SPECIFIC MATERIALS AND EQUIPMENT APPROVED FOR USE BY CANDIDATES

A calculator as approved by TASC (Refer to https://www.tasc.tas.gov.au/students/exams/what-can-i-take-to-my-exam/)

2015 External Examination Information Sheet for PHY415115 Physics.

ASSESSMENT

The following aspects of four (4) of the criteria and their standards described in the course document are externally assessed. These define the expectations for the nature, scope and level of demand of the targeted course content areas.

Criterion 5: demonstrate knowledge and understanding of Newtonian mechanics including gravitational fields

All aspects of Criterion 5 are examinable

Criterion 6: demonstrate knowledge and understanding of principles and theories of electricity and magnetism


Criterion 7: demonstrate knowledge and understanding of general principles of wave motion


Criterion 8: demonstrate knowledge and understanding of the particle nature of light, and atomic and nuclear physics

All aspects of Criterion 8 are examinable.

The examination must include items that give opportunities to demonstrate the standards from rating C to rating A.

Final results will be awarded as a rating of A, B, C, t or z in the above criteria. These ratings are used in determining the final award according to the algorithm in the course document.

https://www.tasc.tas.gov.au/students/exams/rules/

https://www.tasc.tas.gov.au/students/exams/what-can-i-take-to-my-exam/

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EXAMINATION CONTENT

A representative sample3, encompassing a large proportion of the targeted course areas, is used to test the standard of skills, knowledge and understanding of a candidate

The relative weighting4 of items is indicated by:

o relative allocation of marks

o suggested time allocations, and

o the space5 allocated for responses is a guide

If a numerical response to an item is required for further items, then:

o the item takes the form of ‘Show that...’ with the response given to one (1) or two (2) significant figures

o candidates are expected to give their response to three (3) significant figures

No section of an item is to be worth more than 4 marks.

General guidelines for writing items

Items are written:

using language/course-specific terminology as outlined in the course document

using unambiguous English language.

3 Representative sample: a subset of the target course content that accurately reflects the total target course content.

4 Relative weighting: the relative emphasis on the assessment of an item compared with other items within a group, that will influence the final result, that is, the rating.

5 Space: a number of lines provided in the item-and-response booklets indicative of the expected extent of responses.

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EXAMINATION STRUCTURE

The examination paper is divided into four parts:

the four parts are in four separate item-and-response booklets

a set of spare diagrams used in each part is provided in the back of the relevant item-and-response booklet.

The following specifications for each part are outlined in Table 1:

the distribution across the parts of:

o criteria

o course content (topics)

o time and mark allocations

number and type of items.

Relationships between the examination specifications and the written examination items will be mapped each year. (See Attachment 2.)

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Table 1: PHY415115 Physics 2015 Examination Structure

Part Part 1 Part 2 Part 3 Part 4

Criterion (see details in the section Assessment)

Criterion 5 Criterion 6 Criterion 7 Criterion 8

Course Topics Newtonian mechanics including gravitational fields

Principles and theories of electricity and magnetism

General principles of wave motion

The particle nature of light, and atomic and nuclear physics

Number of items From 5 to 7 items, each broken into parts

From 5 to 7 items, each broken into parts



Compulsory items All All All All

Item type(s) (See Attachment 1 for definitions and exemplars)

Context of the item Some extended items are in non-routine contexts.

Scenario of the item Some scenarios of items are real-world scenarios.

Response format A balance of items ranging from short to extended response formats.

Assessment of response Responses range from closed-ended to open-ended.













Suggested time allocation

45 minutes 45 minutes 45 minutes 45 minutes

Mark allocation 40 marks 40 marks 40 marks 40 marks

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ATTACHMENT 1

Written Examination Item types

In these specifications, the term ‘item’ is defined as an individual task to be undertaken by candidates. The task may be divided into several parts.

Item types can be categorised in terms of:

CATEGORY ITEM TYPES AND DEFINTIONS

EXEMPLARS

The context of the item

Routine context

These items require rehearsed skills in Physics, and in familiar contexts.

(Reference: Physics Exam Paper 2013, Part 1, Question 2)

A cricketer hits a ball at an angle of 60 ̊ to the horizontal so that it rises to a vertical height of 15.0 m above the point from which it is hit. The landing point is at the same height as the starting point, as shown in the diagram. Ignore air resistance.

For an angle of 60° and a height of 15m, (a) (i) Calculate the vertical component of the ball’s initial velocity. (1 mark)

(ii) Hence determine the speed at which the ball leaves the cricketer’s bat. (2 marks)

(b) Determine the time of flight of the ball. (2 marks)

(c) How far from the batsman does the ball land? (2 marks)

(d) The batsman later hits the same shot but the ball is caught by a fielder at a distance of 33.0 m from the batsman.

At what height above the ground is the ball caught? (3 marks)

Non-routine context

These items require procedures not previously


A water-powered jet-pack worn by a ‘flyer’ has recently been developed. This jet-pack is driven by a motor and pump mounted in a small boat. A large flexible hose leads to the jet-pack worn by the

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encountered in expected prior learning activities. These require the combination, and sometimes the selection, of a set of skills in unfamiliar contexts.

flyer.

(a) In one particular unit, the pump delivers 49 litres of water per second to the jet-pack. The jet of water is supporting 120 kg of person and equipment in a fixed position. 1.0 L of water has a mass of 1.0 kg. Calculate the speed at which the water is being ejected from the jet nozzle. (3 marks)

(b) Assuming a long enough hose is available, state a factor that would limit the height to which this flyer can rise. Explain your reasoning. (2 marks)

(c) Suppose you had to redesign the system so that it would go to a greater maximum height.

You can

• change the speed of the water without changing the amount of water per second, or

• increase the amount of water per second without changing its speed.Which is the more efficient option? Justify your choice. (2 marks)

The scenario of the item

Real-world scenarios

These items relate principles and theories of Physics to physical phenomena in the real world. The nature of approximations of theory to reality is clearly stated.

(Reference: Physics Exam Paper 2012, Part 3, Question 11).

1. A person throws a cricket ball vertically upwards. The graph shows velocity versus time for the motion of the ball from the time the person starts throwing the ball till the time at which the ball lands on the ground. For simplicity, this graph was drawn assuming that the acceleration

of gravity, g, has a value 10 . (Reference: Exam Paper 2010, Part 1, Question 1).

Calculate the time taken for the proton to travel once around its path, assuming a uniform field.

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The format of response

Short response format

These items are composed of a brief prompt that demands a response to some stimulus material that varies from a single response to a few written points. This sort of item is suited to assessing the candidate’s ability to:

o recall specific information and methods related to key content

o apply rehearsed methods to familiar situations

o demonstrate understanding of key concepts in previously unseen stimulus material.


Ernest Rutherford identified and named α, β and γ particles. He determined their charges by passing the particles through an electric field.

An alpha particle (helium nucleus) travelling at is projected between two parallel plates. The plates have a potential difference of 150.0 kV, with the lower plate being positive; they are 1.5 cm apart and each is 5.0 cm long.

(a) On the diagram, draw the electric field lines in the space between the plates. (1 mark)

(b) Determine, and specify fully, the electric field strength between the plates. (2 marks)

(c) Determine the electric force on the alpha particle. (1 marks)

(d) Determine the acceleration of the alpha particle. (1 mark)

(e) Find the time taken for the alpha particle to traverse the region between plates. (1 mark)

(f) What will the vertical displacement of the alpha particle be as it leaves the plates? (2 marks)

3.0 ´107 ms-1

- - - - - - - - - - - - - - - - - - - -

α

+ + + + + + + + + + + + +

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Extended response format

These items involve lengthy and/or multi stage responses [of increasing complexity]. Greater complexity may be due to one or more of, but not limited to, the following:

o a greater cognitive demand of physics concepts

o the necessity to select appropriate information

o justification of a response via a logical line of reasoning.


The human ear canal (opposite) has similar properties to a closed organ pipe of length 25 mm shown in the simplified diagrams below.

(a) In the two simplified diagrams, show the resonance wave patterns for the fundamental and first overtone. (2 marks)

Fundamental

First overtone

(b) Show that the fundamental frequency is about 3 kHz. (2 marks)

(c) Human ears are particularly sensitive to sounds of frequency about 3 kHz and above about 10 kHz. Explain this using the principles of physics. (3 marks)

(d) The diagrams below show a stethoscope used by doctors to hear a patient’s heartbeat and a typical frequency response of such a stethoscope.

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A stethoscope is essentially a hollow tube with an open end connected to the vibrations within the body of the patient and a closed end in the doctor’s ear.

Explain the three peaks in the graph, given that the total tube length of the stethoscope is about 0.9 m. (3 marks)

Assessment of response

Closed-ended response

These are items for which there is a single ‘correct’ or ‘best’ response.


Stella and her crew, space-travellers from Earth, visit the planet Minerva in a distant planetary system. A year on Minerva is equal to 200 Earth-days. One day on Minerva is12 Earth-hours.

Mass of Earth = 5.97 x 1024

kg Radius of Earth = 6371 km

Radius of Earth’s orbit = 1.50 x 108

km (a) The mother-ship of Stella’s crew continually orbits Minerva every 100 minutes at anorbital radius of 4500 km.

Show that the mass of Minerva is about 1.5 x 1024

kg.

Rel

ativ

e lo

ud

nes

s o

f so

un

d

0 100 200 300 400 500 Frequency (Hz)

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Open-ended response

These are items for which there may be multiple correct responses OR in which the quality of the argument and/or the expression is being assessed.


In the medical physics unit of a hospital, cancer cells may be killed by using a beam of either high-energy X-rays or gamma rays. Both X-rays and gammas are ionising electromagnetic radiation; the X-rays can be produced by accelerating electrons in a Coolidge tube and the gammas obtained from a radioisotope such as Co-60. The rays are concentrated into a narrow beam focussed on the target.

(a) In terms of safety, convenience and flexibility, give two reasons why the use of X-rays may be preferred to gammas. (Assume that X-rays and gammas have the same effect on cancer cells.)

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ATTACHMENT 2

PHY415115 Physics Written Examination 2015 Mapping

The Setting Examiner designs examination items to adhere to the External Assessment Specifications (see Table 1). During the writing and critiquing of the examination, the Setting Examiner will map the PHY415115 Physics examination to the course document and external assessment specifications. This may be achieved through the mapping grids given in Tables 2 – 13.

Mapping provides a summary of relationships between examination items and:

item type

relative importance/weighting

content

achievement standard, and

item rating.

Mapping is designed primarily to assist the Setting Examiner to:

see at a glance the range of item types, content statements, and achievement standards used in the examination paper, and

check for:

o representative sampling, and

o adherence to the examination structure specifications.

Checklist

The Setting Examiner conducts a final check for adherence of the written examination to the external assessment specifications by completing a checklist. (See Table 14.)

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PHY415115 Physics 2015 Written Examination Mapping Grids

Part 1: Newtonian mechanics including gravitational fields

Table 2: Criteria being assessed

Criterion 5 Standard Item numbers

Possible ratings of response

5.1 Fundamental principles and theories

5.2 Use of appropriate formulae to solve numerical problems

5.3 Using and generating data

5.4 Interpretation of problems; making predictions

Table 3: Course coverage

Topic Item numbers

Motion

Momentum and Newton’s Laws

Work, Energy and Power

Circular Motion

Gravitational Fields

Table 4: Item type

Item type Item numbers

Context of the item

Some non-routine items

Scenarios of items

Some real-world scenarios, stating approximations to reality

Response format





Open-ended response

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Part 2: Principles and theories of electricity and magnetism









Topic Item numbers

Static electricity

Magnetic fields

Table 7: Item type


Context of the item


Scenarios of items


Response format





Open-ended response

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Part 3: General principles of wave motion









Topic Item numbers

Wave interactions

Wave interference

Table 10: Item type


Context of the item


Scenarios of items


Response format





Open-ended response

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Part 4: The particle nature of ight, and atomic and nuclear physics









Topic Item numbers

Particle Nature of Light

Energy Levels of Atoms

Radioactivity and its Detection

Radioactive Decay

Table 13: Item type


Context of the item


Scenarios of items


Response format





Open-ended response

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Checklist

Table 14: PHY415115 Physics 2015 Written Examination Checklist

Part 1: Newtonian mechanics including gravitational fields

☐ Assesses all aspects of Criterion 5

☐ Items give opportunities to demonstrate standards from rating C to rating A

☐ Marks add up to 40

☐ Includes a representative sample of course content from Newtonian mechanics including gravitational fields

☐ Included 5 – 7 items, each broken into parts

☐ Some extended items are in non-routine contexts

☐ Some scenarios are real-world with approximations to reality stated

☐ Responses are a balance range from short to extended formats

☐ Responses range from closed-ended to open-ended

Part 2: Principles and theories of electricity and magnetism




☐ Includes a representative sample of course content from principles and theories of electricity and magnetism






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Part 3: General principles of wave motion




☐ Includes a representative sample of course content from general principles of wave motion






Part 4: The particle nature of light, and atomic and nuclear physics




☐ Includes a representative sample of course content from the particle nature of light, and atomic and nuclear physics






Documents

Physics - Department of Education · These definitions are to be in sufficient detail that they will serve both as a blueprint, describing all ... and theories of Physics to physical