South Pacific Form Seven Certificate PHYSICS 2004 INSTRUCTIONS Write your Student Personal Identification Number (SPIN) on the top right hand corner of this page and on the fold-out flap on the last page. Answer ALL QUESTIONS . Write your answers in the spaces provided in this booklet. If you need more spaces for answers, ask the Supervisor for extra paper. Write your SPIN on all extra sheets used and clearly number the questions. Attach the extra sheets at the appropriate places in this booklet. The questions are organised under the headings below, with allocations of marks and suggested times indicated. The total marks assigned to questions is 152. In addition to this, four marks will be awarded for correct use of significant figures and a further four marks will be awarded for correct use of units of measurement. Time Questions One and Two Waves 30 marks 36 minutes Questions Three to Six Mechanics 53 marks 63 minutes Questions Seven to Nine Electricity and Electromagnetism 45 marks 53 minutes Questions Ten and Eleven Atomic and Nuclear Physics 24 marks 28 minutes ------------- 152 marks + 8 marks ------------- Some useful formulae are given on Sheet 109/2 provided. Check that this booklet contains pages 2-24 in the correct order and that none of these pages is blank. YOU MUST HAND THIS BOOKLET TO THE SUPERVISOR AT THE END OF THE EXAMINATION. Student Personal Identification Number (SPIN) QUESTION and ANSWER BOOKLET Time allowed: Three hours TOTAL MARKS 160 Marker Code
Transcript
South Pacific Form Seven Certificate
PHYSICS 2004
INSTRUCTIONS
Write your Student Personal Identification Number (SPIN) on the top right hand corner of this page and on the fold-out flap on the last page. Answer ALL QUESTIONS. Write your answers in the spaces provided in this booklet. If you need more spaces for answers, ask the Supervisor for extra paper. Write your SPIN on all extra sheets used and clearly number the questions. Attach the extra sheets at the appropriate places in this booklet. The questions are organised under the headings below, with allocations of marks and suggested times indicated. The total marks assigned to questions is 152. In addition to this, four marks will be awarded for correct use of significant figures and a further four marks will be awarded for correct use of units of measurement.
Time Questions One and Two Waves 30 marks 36 minutes Questions Three to Six Mechanics 53 marks 63 minutes Questions Seven to Nine Electricity and Electromagnetism 45 marks 53 minutes Questions Ten and Eleven Atomic and Nuclear Physics 24 marks 28 minutes -------------
152 marks + 8 marks -------------
Some useful formulae are given on Sheet 109/2 provided. Check that this booklet contains pages 2-24 in the correct order and that none of these pages is blank. YOU MUST HAND THIS BOOKLET TO THE SUPERVISOR AT THE END OF THE EXAMINATION.
Student Personal Identification Number (SPIN)
QUESTION and ANSWER BOOKLET Time allowed: Three hours
TOTAL MARKS
160
Marker Code
Marker Code
2
WAVES (30 marks; 36 minutes)
QUESTION ONE: THE GUITAR (16 marks)
A guitarist makes musical notes by strumming or plucking the guitar strings and making them vibrate. As part of tuning the guitar, the second string from the top (the “A” string) is made to vibrate.
A guitar
(a) Sketch the fundamental (first harmonic) standing wave formed on the string. Label any nodes, N.
(2 marks)
(b) State whether the wave on the string is transverse or longitudinal.
(e) State two methods the guitarist can use to alter the frequency produced on the “A” string. For each method explain in terms of physical principles how the guitarist's actions alter the frequency that is heard.
Speed of light in air = 3.00 x 108 m s-1 The diagram below shows a view through a compact disc (CD). The metal layer of a CD is the recording surface and contains narrow ridges and valleys.
A narrow beam of infra-red, monochromatic laser light of wavelength 7.80 x 10-7 m is directed towards the CD. When light reflects from a narrow ridge some of it interferes destructively with light reflected from nearby valleys.
(a) Explain the meaning of the term monochromatic.
Acceleration due to gravity = 9.80 m s-2 A climber of mass 65.0 kg, carrying a bag of mass 18.0 kg on his back, is in the process of moving one foot to a new position on a cliff face. The forces on the climber, due to his grip on the cliff face, are shown in the diagram. The climber is momentarily at rest as he searches for a foothold, and can be considered to be in equilibrium.
(a) Calculate the combined mass and weight of the climber and his bag.
QUESTION FOUR: LONDON’S MILLENNIUM BRIDGE (14 marks) As part of London’s Millennium (Year 2000) celebrations a foot-bridge was built across the Thames River. Shortly after the bridge was opened it was discovered that pedestrians could make the bridge sway from side to side. The bridge can be considered to be a spring undergoing simple harmonic motion (SHM). The central walkway has a mass of 80.0 x 103 kg and oscillates with a period of 2.40 s. The maximum movement at the centre of the bridge was 0.600 m from one side to the other.
(a) Show that the angular frequency of this system is 2.62 rad s-1.
maximum acceleration = _____________________________ (2 marks) The bridge design includes damping mechanisms which bring the motion to a halt in 7.20 s. (g) The bridge is set oscillating. Sketch a graph of amplitude against time for the damped
SHM of the bridge. Label the axes and include values for the amplitude and time. Assume that the oscillation of the bridge is at maximum amplitude at t = 0.
(3 marks)
P.9 9
Q4 14
10
QUESTION FIVE: THE CANOE (8 marks)
A 60.0 kg student is paddling her canoe, of mass 18.0 kg, across a calm lake with a single bladed paddle of mass 2.00 kg. Previous efforts against a machine established that the student exerts a constant pull of 50.0 N, with each stroke taking 2.00 s.
(a) Show that the impulse transferred to the canoe by each stroke of the paddle is 100 N s.
Consider the case of an asteroid hitting Earth. The mass of the asteroid is 2.00 x 1020 kg and its speed is 3.00 x 105 m s-1. It collides with the Earth as shown in the diagram and imbeds itself into the Earth at its collision point.
(e) Show that the angular momentum of the asteroid just before the collision, about the centre of the Earth, is 3.82 x 1032 kg m2 s-1.
(g) Calculate the new period, in hours, of the Earth’s rotation after the collision with the asteroid has occurred. (The rotational inertia associated with the asteroid can be ignored).
If the polar ice caps melt a large volume of water will be released into the ocean. This could cause the rotational period of the Earth about its axis to alter.
(h) Using physical principles, discuss the above statement.
ELECTRICITY AND ELECTROMAGNETISM (45 marks; 53 minutes)
QUESTION SEVEN: DC ELECTRICITY (9 marks) The voltage divider circuit is extremely common in modern day electronics. A student makes a voltage divider circuit, as shown in the diagram below, from a 66.0 Ω resistor (between A and B) and a 94.0 Ω resistor (between B and C), connected in series with a 12.0 V battery. The student connects a voltmeter across the 94.0 Ω resistor.
(a) Calculate the voltage across the 94.0 Ω resistor.
QUESTION EIGHT: AN UNUSUAL CAPACITOR (18 marks) Permittivity of free space = 8.84 x 10-12 F m-1 There are various methods of constructing a variable capacitor. One way is shown in the diagram below. Two pieces of square aluminium sheet (0.217 m by 0.217 m) are separated by a tight-fitting piece of cardboard of thickness d = 2.00 x 10-3 m. The capacitance can be altered by changing the area of overlap between the two aluminium sheets.
(a) Show that the surface area of the aluminium is 0.0471 m2.
(b) The capacitance can be reduced by decreasing the area of overlap of the aluminium sheets by sliding one of them sideways. By considering the electric field and the charge on the capacitor explain why the capacitance decreases.
(h) Sketch a graph to show how the current across the capacitor varies with time while it is charging. Label any intercepts and asymptotes.
(4 marks)
P.18 6
Q8 18
19
QUESTION NINE: THE ELECTRIC TOOTHBRUSH (18 marks) An electric toothbrush can be recharged by sitting it in a charging unit which is joined to an AC power supply.
The bottom of the toothbrush contains a coil of wire connected to a rechargeable battery. In the charging unit there is another coil which is connected to the AC power supply. There is no physical contact between the two coils.
(a) Explain how the presence of a voltage in the base coil can cause a voltage to exist in the toothbrush coil.
It is known that for every particle there exists an antimatter particle. These antimatter particles are identical in mass but opposite in charge. When a particle encounters its corresponding antiparticle, the two undergo annihilation – all their mass is transformed into energy in the form of gamma radiation.
The following is an example of a typical annihilation reaction.
QUESTION ELEVEN: THE PHOTOELECTRIC EXPERIMENT (14 marks) Charge on the electron = -1.60 x 10–19 C Speed of light = 3.00 x 108 m s–1 Planck’s constant = 6.63 x 10–34 J s.
In a photoelectric experiment, red light of frequency 5.00 x 1014 Hz shines on to a sodium metal surface which has a work function of 3.67 x 10-19 J.
(a) Show, by calculation, why no photoelectrons are emitted.
(c) Blue-violet light of frequency 7.00 x 1014 Hz is shone on to the sodium metal surface. Calculate the maximum kinetic energy of the emitted photoelectrons.
![EDUCATIONAL QUALITY AND ASSESSMENT PROGRAMME [EQAP] · This prescription defines the requirements for assessment in the South Pacific Form Seven Certificate Accounting examination.](https://static.documents.pub/doc/80x56/6076f728277ca63e7f625484/educational-quality-and-assessment-programme-eqap-this-prescription-defines-the.jpg)
![SOUTH PACIFIC FORM SEVEN CERTIFICATE [SPFSC]](https://static.documents.pub/doc/80x56/61bd390a61276e740b109457/south-pacific-form-seven-certificate-spfsc.jpg)
