physics - department of education...around an invisible object called sgra*. one such star is called...
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© Copyright for part(s) of this examination may be held by individuals and/or organisations other than the Office of Tasmanian Assessment, Standards and Certification.
Tasmanian Certificate of Education
External Assessment 2019
PHYSICS (PHY415115)
PART 1 - NEWTONIAN Time allocated: 45 minutes
On the basis of your performance in this examination, the examiners will provide a result on the following
criterion taken from the course document:
Criterion 5 Identify and apply principles of Newtonian mechanics including gravitational fields.
PLACE YOUR CANDIDATE
LABEL HERE
Candidate Instructions:
1. You MUST make sure that your responses to the questions in this examination paper will show
your achievement in the criterion being assessed.
2. Answer ALL questions.
3. Answers must be written in the spaces provided on the examination paper.
4. You should make sure you answer all parts within each questions so that the criterion can be
assessed.
5. This examination is 3 hours in length. It is recommended that you spend approximately
45 minutes in total answering the questions in this booklet.
6. The External Examination Information Sheet for Physics can be used throughout the examination.
7. All written responses must be in English.
8. TASC approved calculator can be used.
Pages: 12
Questions: 6
Attachment: Information Sheet
Total: /40
PHY415115 Page 2 of 12
Show all working in your answers to numerical questions. Some credit will be given for un-simplified answers. Credit cannot be given for an incorrect answer unless it is accompanied by details of the working. Appropriate units must be included. Note:
When candidates are asked to ‘show that’:
o a candidate should calculate their own answer to three significant figures and use this subsequently.
o a candidate who is unable to determine the required value should use the value
given by the examiner in subsequent parts to the question.
A spare set of diagrams has been provided in the back of the answer booklet for you to use if required. If you use the spare diagrams, you MUST indicate you have done so in your answer to that question.
Additional Instructions for Candidates
PHY415115 Page 3 of 12
Question 1
A block of wood of mass 550 g is pulled up a rough ramp sloped at 20° by a piece of string at a
constant speed of 0.5 ms -1. The string is pulling with a force of 3 N.
(a) Calculate the frictional force between the ramp and the block of wood. (3 marks)
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(b) Calculate the total work done each second by the force in the string. (1 mark)
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Question 2
A car has a good-luck charm of mass 20 g hanging from the rear-view mirror. As the car
accelerates forward, the charm swings back to an angle of 38° to the vertical.
(a) (i) Draw the forces on the charm on the diagram above. (1 mark)
(ii) Calculate the acceleration of the car. (2 marks)
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After this acceleration, the car now travels around a corner at 120 km h -1 to the RIGHT. The
charm now hangs at 38° to the vertical.
(b) (i) Sketch the charm in the diagram above and show the forces on it. (1 mark)
(ii) Calculate the RADIUS of the turn that is being made. (2 marks)
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PHY415115 Page 5 of 12
Question 3
Henry Cavendish first measured the mass of the Earth by initially measuring the gravitational
force between masses of lead at various distances.
Consider the data below that represents the forces between two masses of 20 kg and 50 kg at
various distances.
r (metres) 0.200 0.250 0.300 0.350
F (Newtons x 10-6) 1.70 1.07 0.74 0.54
(a) What formula will allow a straight line graph to be created from this data? (1 mark)
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(b) In the blank row in the table above, complete values that will create a straight line.
(1 mark)
(c) Graph the values on the grid paper below. (2 marks)
(d) Calculate the Universal Gravitational Constant from your graph, showing all working.
(2 marks)
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PHY415115 Page 6 of 12
Question 4
Space agencies like NASA use planets to speed up or slow down space probes and to redirect
the probes to new trajectories. This is often called “sling-shotting”.
Consider Voyager 2 when, in 1977, it passed Jupiter on its way to the outer planets and
eventually to outer space.
It approached Jupiter at 10 kms -1, changed direction through 90° and left at 20 kms -1 as illustrated
in the diagram above. The mass of Voyager 2 is 820 kg.
The mass of Jupiter is 1.90 x 1027 kg.
(a) Draw a suitable diagram allowing the CHANGE in momentum of Voyager to be calculated.
(2 marks)
(b) Show that the magnitude of the change in momentum is about 1.8 x 107 kgms -1.
(2 marks)
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Question 4 (continued)
(c) The time to pass Jupiter was 15 hours. Calculate the magnitude of the average force on the
probe. (2 marks)
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(d) Calculate the magnitude of the change in momentum of Jupiter. (1 mark)
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(e) What effect will this interaction have on the orbit of Jupiter around the Sun?
Justify your answer. (2 marks)
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(f) How might NASA slow down a probe by passing a planet? (2 marks)
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Question 5
Astronomers have been studying the motion of large stars in the middle of our Galaxy in orbit
around an invisible object called SgrA*.
One such star is called S2. Assume its orbit is circular. Its period is 16.1 years and radius of orbit
is 1.30 x 1014 m.
(a) Find the average speed of the star S2 in kms -1. (2 marks)
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(b) Find the mass of the invisible object SgrA*. (3 marks)
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Question 5 (continued)
(c) If the mass of our Sun is 2 x 1030 kg, how many Sun-like stars does this mass represent?
(1 mark)
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(d) What might the invisible object, SgrA*, be? (1 mark)
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Question 6
Alan Shepard hit a golf ball on the Moon (g = 1.62 ms -2) in 1971.
Suppose he hit an identical shot on Earth (g = 9.81 ms -2) at 140 kmh -1 at 40° to the
horizontal.
(a) Calculate the time the ball is above the ground on Earth. Ignore the air resistance and
assume the ground is flat. (3 marks)
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(b) Calculate the distance travelled by such a ball on Earth. (1 mark)
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(c) Show that the equivalent time on the Moon is about 6 times larger. (1 mark)
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(d) Compare the horizontal distance travelled on the Moon to Earth. (1 mark)
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END OF PART 1
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Question 2(a) (i)
Question 2(b) (i)
Question 6 (c)
Spare Diagrams
PHY415115 Page 12 of 12
This examination paper and any materials associated with this examination (including answer booklets, cover sheets, rough note
paper, or information sheets) remain the property of the Office of Tasmanian Assessment, Standards and Certification (TASC).
© Copyright for part(s) of this examination may be held by individuals and/or organisations other than the Office of Tasmanian Assessment, Standards and Certification.
Tasmanian Certificate of Education
External Assessment 2019
PHYSICS (PHY415115)
PART 2 - ELECTROMAGNETISM
Time allocated: 45 minutes
On the basis of your performance in this examination, the examiners will provide a result on the following
criterion taken from the course document:
Criterion 6 Identify and apply principles and theories of electricity and magnetism.
Total: /40
PLACE YOUR CANDIDATE
LABEL HERE
Candidate Instructions
1. You MUST make sure that your responses to the questions in this examination paper will show
your achievement in the criterion being assessed.
2. Answer ALL questions.
3. Answers must be written in the spaces provided on the examination paper.
4. You should make sure you answer all parts within each questions so that the criterion can be
assessed.
5. This examination is 3 hours in length. It is recommended that you spend approximately 45 minutes
in total answering the questions in this booklet.
6. The External Examination Information Sheet for Physics can be used throughout the examination.
7. All written responses must be in English.
8. TASC approved calculator can be used.
Pages: 12
Questions: 6
Attachment: Information Sheet
PHY415115 Page 2 of 12
Show all working in your answers to numerical questions. Some credit will be given for un-simplified
answers. Credit cannot be given for an incorrect answer unless it is accompanied by details of the working.
Appropriate units must be included.
Note:
When candidates are asked to ‘show that’:
o a candidate should calculate their own answer to three significant figures and use this subsequently.
o a candidate who is unable to determine the required value should use the value
given by the examiner in subsequent parts to the question.
A spare set of diagrams has been provided in the back of the answer booklet for you to use if required. If you use the spare diagrams, you MUST indicate you have done so in your answer to that question.
Additional Instructions for Candidates
PHY415115 Page 3 of 12
Question 7
When a plastic rod is rubbed on cloth, it acquires an electrostatic charge. This charged rod is able
to lift light pieces of torn paper.
(a) Describe how it can lift the paper using diagrams and referring to the appropriate physics
laws. (3 marks)
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A Faraday cage does not let external electrostatic
effects into it.
(b) Describe why a closed, charged metal cage has no electric
field inside due to an external charge. (3 marks)
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Question 8
Two charges of +2 nC and -4 nC are arranged as in the diagram below. They are separated by
a distance of 3 cm.
(a) Find the magnitude of the total field strength at the vertex of an equilateral triangle P.
(4 marks)
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(b) Hence, find the magnitude of the force on a charge of +2 pC placed at this point.
(1 mark)
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Question 8 (continued)
(c) Sketch the total electric field around the two charges on the diagram below. (3 marks)
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+2 nC -4 nC
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Question 9
Three equal sized charges A, B and C are placed as in the diagram below. A and B are positively
charged while C is negatively charged.
Charge A exerts a force of 4.00 N on charge B.
(a) Find the size of the force that charge C exerts on charge B. (2 marks)
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(b) Calculate the size of the TOTAL force on charge B. (3 marks)
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(c) Find the DIRECTION of the total force on charge B with respect to the line AB. (2 marks)
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Question 10
An Airbus 350 is flying north though the Earth’s magnetic field. The field has a flux density of
1.90 x 10-5 T at an angle of declination of -70°.
If the plane is flying at 900 kmh -1 and the wingspan is 64.75 m, find
(a) The potential difference generated across the wing. (2 marks)
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(b) Determine the sign of the charge on the WEST wing. (2 marks)
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(c) Why is it NOT possible to use this potential difference to power the electronics of the
aircraft? (2 marks)
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PHY415115 Page 8 of 12
Question 11
A wire 2 cm long is placed at right angles to a magnetic field of a magnet placed on an electronic
balance. The readings on the balance are in grams.
The balance is zeroed then a current is passed through the wire.
A graph of current through the wire and balance measurement in grams is shown below.
(a) Calculate the slope of the graph in NEWTONS per amp. (2 marks)
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Question 11 (continued)
(b) From the slope, find the Magnetic Flux Density, B, in tesla, of the magnet. (2 marks)
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(c) What effect would rotating the wire to 45° in the horizontal plane have on the slope of the
graph? (2 marks)
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Question 12
A beam of electrons is accelerated through 2.4 kV and allowed to pass into a magnetic field of
flux density 11.5 mT at right angles to the field.
(a) Show that the speed of the electrons is about 3 x 107 ms -1. (2 marks)
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(b) Determine the FORCE on the electrons while in the magnetic field. (2 marks)
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(c) Calculate the radius of the path of the electrons. (1 mark)
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(d) Calculate the frequency of the electron orbit. (2 marks)
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END OF PART 2
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Question 8 (c)
Spare Diagrams
+2 nC -4 nC
PHY415115 Page 12 of 12
This examination paper and any materials associated with this examination (including answer booklets, cover sheets, rough note
paper, or information sheets) remain the property of the Office of Tasmanian Assessment, Standards and Certification (TASC).
© Copyright for part(s) of this examination may be held by individuals and/or organisations other than the Office of Tasmanian Assessment, Standards and Certification.
Tasmanian Certificate of Education External Assessment 2019
PHYSICS (PHY415115)
PART 3 - WAVES
Time allocated: 45 minutes
On the basis of your performance in this examination, the examiners will provide a result on the following criterion taken from the course document:
Criterion 7 Identify and apply general principles of wave motion.
Total: /40
PLACE YOUR CANDIDATE LABEL HERE
Candidate Instructions
1. You MUST make sure that your responses to the questions in this examination paper will show your achievement in the criterion being assessed.
2. Answer ALL questions.
3. Answers must be written in the spaces provided on the examination paper.
4. You should make sure you answer all parts within each questions so that the criterion can be assessed.
5. This examination is 3 hours in length. It is recommended that you spend approximately 45 minutes in total answering the questions in this booklet.
6. The Information Sheet for Physics can be used throughout the examination.
7. All written responses must be in English.
8. TASC approved calculator can be used.
Pages: 16 Questions: 6 Attachment: Information Sheet
PHY415115 Page 2 of 16
Show all working in your answers to numerical questions. Some credit will be given for un-simplified answers. Credit cannot be given for an incorrect answer unless it is accompanied by details of the working. Appropriate units must be included.
Note:
• When candidates are asked to ‘show that’:
o a candidate should calculate their own answer to three significant figures and use this subsequently.
o a candidate who is unable to determine the required value should use the value
given by the examiner in subsequent parts to the question. • A spare set of diagrams has been provided in the back of the answer booklet for you to
use if required. If you use the spare diagrams, you MUST indicate you have done so in your answer to that question.
Additional Instructions for Candidates
PHY415115 Page 3 of 16
Question 13
In the diagram below, a pulse is directed down two strings, one free at one end, the other fixed at one end.
(a) On the diagram above sketch the subsequent reflection from each end. (2 marks)
(b) Explain your answer to part (a) in terms of forces on the string at the end limit and the subsequent motion of the string;
(i) for the free-end string. (2 marks)
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(ii) for the fixed-end string. (2 marks)
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Question 14
One type of organ pipe is open at both ends (a flue pipe) and is shown below.
(a) Sketch the fundamental standing wave generated in this pipe. (2 marks)
(b) Suppose a pipe is being designed to produce a frequency of 32 Hz and the speed of sound in the concert hall is 339 ms-1, what length of pipe needs to be produced? (2 marks) ..............................................................................................................................................
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(c) A concert hall, with the large pipe in the organ, has heating installed and the ambient temperature is raised from 12°C to 20°C.
The speed of sound is given by the formula:
v = 331.3 + 0.606 T ms-1 where T is in °C.
Calculate the new frequency of the pipe. (3 marks) ..............................................................................................................................................
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Question 14 (continued)
(d) What effect might raising the temperature of a concert hall have on the sound of the organ? (1 mark) ..............................................................................................................................................
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Question 15
A rainbow is formed when light, usually from the Sun, enters water droplets and both refracts and reflects to leave the droplet on a path to a person’s eye.
Consider a single droplet with white light incident on it as in the diagram below.
For RED light, n = 1.331. Suppose the angle of incidence is 60°. (a) Calculate the angle of refraction at A of the red light into the droplet. (2 marks)
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(b) At the point of the reflection at B:
(i) Calculate the critical angle of reflection. (2 marks)
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Question 15 (continued)
(ii) Is the incident red light fully internally reflected? Justify. (2 marks)
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(c) At point C, where the light leaves the droplet, what will be the angle relative to the normal? (1 mark) ..............................................................................................................................................
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(d) Blue light has a refractive index of 1.345 in water. On the diagram below sketch the path of the blue light from A through the raindrop and into the air. (2 marks)
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PHY415115 Page 8 of 16
Question 16
A domestic microwave oven operates at a frequency of 2.45 GHz.
(a) Calculate the wavelength of the microwave emission. (1 mark) ..............................................................................................................................................
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(b) The interior dimensions of a common brand of microwave oven are:
36.7 cm x 36.7 cm x 24.5 cm.
How many complete waves do these values represent? (2 marks) ..............................................................................................................................................
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(c) If the walls, being metal, are nodal, on the diagram below, sketch the pattern of standing waves ACROSS the width of the microwave oven. (2 marks)
Question 16 continues.
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Question 16 (continued)
(d) Explain why many microwave ovens have rotating glass plates on which items that are intended to be heated are placed. (1 mark)
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(e) A microwave oven turned on without a food or liquid inside to be heated can cause the wave generator (a magnetron) to fail due to overloading. Give a reason why this may happen. (1 mark)
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PHY415115 Page 10 of 16
Question 17
A single slit is illuminated with coherent, monochromatic light. A pattern is observed on a sheet of paper placed 1 m away as shown in the diagram.
(a) What is meant by the term “monochromatic”? (2 marks) ..............................................................................................................................................
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(b) What is meant by the term “coherent” in this context? (2 marks) ..............................................................................................................................................
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Question 17 (continued)
(c) Using the diagram of a single slit below, explain how a pattern can be created on the sheet of paper. (2 marks)
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Question 18
Nobel Prize winners for 1915, William and Lawrence Bragg, showed that X Rays could create interference patterns using crystals. Successive layers of atoms (or ions) can reflect X Rays as below.
(a) Show from the diagram that the TOTAL path difference between ray AC, and ray A’C’, when
going from the source to the detector is given by the equation:
Path Difference = 2dsinθ (2 marks)
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(b) X Rays of wavelength 1.00 x 10-10 m are incident on a crystal of sodium chloride (NaCl).
A bright spot is observed on a detector at an angle of 4.48° to the surface of the crystal. Calculate the distance between the layers of atoms (ions). (2 marks) ..............................................................................................................................................
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END OF PART 3
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PHY415115 Page 13 of 16
Question 13 (a)
Question 14 (a)
Question 15 (d)
Spare Diagrams
PHY415115 Page 14 of 16
Question 16 (c)
Question 18 (c)
Spare Diagrams
PHY415115 Page 15 of 16
BLANK PAGE
PHY415115 Page 16 of 16
This examination paper and any materials associated with this examination (including answer booklets, cover sheets, rough note paper, or information sheets) remain the property of the Office of Tasmanian Assessment, Standards and
Certification (TASC).
© Copyright for part(s) of this examination may be held by individuals and/or organisations other than the Office of Tasmanian Assessment, Standards and Certification.
Tasmanian Certificate of Education
External Assessment 2019
PHYSICS (PHY415115)
PART 4 – TWENTIETH CENTURY
Time allocated: 45 minutes
On the basis of your performance in this examination, the examiners will provide a result on the
following criterion taken from the course document:
Criterion 8 Identify and apply principles of the wave-particle nature of light, atomic and nuclear
physics and models of the nucleus and nuclear processes.
Total: /40
PLACE YOUR CANDIDATE
LABEL HERE
Candidate Instructions
1. You MUST make sure that your responses to the questions in this examination paper will show
your achievement in the criterion being assessed.
2. Answer ALL questions.
3. Answers must be written in the spaces provided on the examination paper.
4. You should make sure you answer all parts within each questions so that the criterion can be
assessed.
5. This examination is 3 hours in length. It is recommended that you spend approximately 45 minutes
in total answering the questions in this booklet.
6. The Information Sheet for Physics can be used throughout the examination.
7. All written responses must be in English.
8. TASC approved calculator can be used.
Pages: 16
Questions: 6
Attachment: Information Sheet
PHY415115 Page 2 of 16
BLANK PAGE
PHY415115 Page 3 of 16
Show all working in your answers to numerical questions. Some credit will be given for un-simplified
answers. Credit cannot be given for an incorrect answer unless it is accompanied by details of the
working. Appropriate units must be included.
Note:
When candidates are asked to ‘show that’:
o a candidate should calculate their own answer to three significant figures and use this subsequently.
o a candidate who is unable to determine the required value should use the value
given by the examiner in subsequent parts to the question.
A spare set of diagrams has been provided in the back of the answer booklet for you to use if required. If you use the spare diagrams, you MUST indicate you have done so in your answer to that question.
Additional Instructions for Candidates
PHY415115 Page 4 of 16
Question 19
A phototube consists of a curved metal plate (usually caesium metal) with a thin wire acting as the
collector at the centre of the plate, all housed in a vacuum.
The circuit above is designed to study the currents created by shining light of different
wavelengths on the metal in the phototube.
(a) (i) What is the purpose of the filters between the light source and the metal plate?
(1 mark)
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(ii) Suggest a more precise method of supplying known wavelengths to the metal plate.
(1 mark)
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Question 19 (continued)
(b) Why in this study is the NEGATIVE terminal of the cell in the circuit connected to the central
wire? (2 marks)
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(c) What is the value on the microammeter when the “Stopping Voltage” is reached?
(1 mark)
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PHY415115 Page 6 of 16
Question 20
The Voyager 1 spacecraft was launched in 1977. It is now on the limits of the Solar System. It is
powered by a 238PuO2 nuclear power source that uses the decay of the 238Pu by decay to create
the energy to run its systems.
94
238 Pu ® 92
234 U + 2
4He
94
238 Pu 238.049553 u 92
234 U 234.040950 u 2
4 He 4.001506 u
(a) Why was it not possible to use solar panels for such a trip beyond Pluto? (1 mark)
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(b) Calculate the energy emitted in each decay in both MeV and J. (3 marks)
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Question 20 continues.
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Question 20 (continued)
(c) The power unit initially created 470 W for the electronics but it was only 5% efficient.
Show that the total energy each second created by the plutonium was approximately 9000 W.
(1 mark)
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(d) Calculate the number of decays each second needed to generate this power.
(2 marks)
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(e) If the half-life 238Pu is 87.7 years, calculate the number of atoms needed to create this power.
(2 marks)
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(f) Hence, calculate the mass of 238Pu needed in the power source. (2 marks)
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Question 21
Iron-56 is one of the most stable elements. 26
56 Fe 55.9349375 u
(a) Calculate the binding energy of Fe-56. (3 marks)
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(b) Calculate the binding energy per nucleon. (1 mark)
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Question 21 (continued)
(c) Referring to the chart above, describe how energy can be obtained both from light elements
and heavy elements but not from elements near Fe-56. (3 marks)
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Question 22
Tungsten is commonly used as the target for high energy electrons for the production of X Rays in
hospitals.
The first three (3) energy levels for tungsten is shown in the diagram.
(a) Calculate the three spectral line energies that can be created by electrons transitioning to
the n = 1 level from the n = 2 and n = 3 levels. (2 marks)
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(b) Calculate the wavelengths that these correspond to. (2 marks)
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Question 22 continues.
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Question 22 (continued)
(c) The metal target is bombarded with electrons through a potential difference of 100 kV.
Calculate the shortest wavelength X Ray that can be produced through acceleration
processes. (2 marks)
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(d) Sketch a wavelength vs intensity graph for the above bombardment, incorporating the
wavelengths calculated in parts (b) and (c). (2 marks)
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(x 10-10 m)
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Question 23
Electrons and electromagnetic radiation can exhibit similar interference and diffraction properties.
Consider electrons moving at 3 x 104 ms -1.
(a) Calculate the wavelength that these electrons exhibit in interference and diffraction
situations. (2 marks)
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(b) What part of the electromagnetic spectrum would show similar wavelike properties?
(1 mark)
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(c) Compare the momentum of a photon of this wavelength to the momentum of the electron.
Justify your answer. (2 marks)
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Question 24
Search and rescue craft use infrared detectors as well as optical detectors, for finding lost people.
A human body is at a typical temperature of 37°C.
(a) Calculate the wavelength at which a human body shines at its brightest. (2 marks)
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(b) Under what conditions will infrared detection of humans work best? Justify your answer.
(2 marks)
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END OF PART 4
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Question 22 (d)
Spare Diagram
(x 10-10 m)
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BLANK PAGE
PHY415115 Page 16 of 16
This examination paper and any materials associated with this examination (including answer booklets, cover sheets,
rough note paper, or information sheets) remain the property of the Office of Tasmanian Assessment, Standards and
Certification (TASC).