TIMES : SPM2009 Spot Questions - Physics (Kertas 2)

a) Base on Diagram 1,
i) Label the period using the symbol T. [1 mark]
ii) What is the period of the oscillation?
....................................................................................................................................................................
[1 mark]

b) What is meant by amplitude?
....................................................................................................................................................................
[1 mark]

c) If the spring is undergoing damping, what will happen to the amplitude of the oscillation?
....................................................................................................................................................................
[1 mark]

 

(ii) 0.2 s

(b) Amplitude of a wave is the maximum displacement of a medium particle from its mean (stationary) position.

(c) Decreases with time

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 (a) Name this natural phenomenon as observed by the driver.
....................................................................................................................................................................
[1 mark]

(b) State the physics concept that is involved in this phenomenon.
....................................................................................................................................................................
[1 mark]

(c) (i) How is the density of the cool air compare to the density of the warm air?
....................................................................................................................................................................
[1 mark]

(ii) When light rays propagates from a denser medium to a less dense medium,
state what happen to the direction of the refracted rays.
....................................................................................................................................................................
[1 mark]

(iii) Complete Diagram 2.2 to show the formation of the natural phenomenon
as shown in Diagram 2.1.

(a) Mirage

(b) Total internal reflection

(c) (i) Density of the cool air is greater than the density of the warm air

(ii) The light rays will be refracted away from the normal

(iii)

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 (a) Name a physics quantity that relates the mass and velocity.
....................................................................................................................................................................
[1 mark]

(b) State the type of energy that is possessed by the running cheetah.
....................................................................................................................................................................
[1 mark]

(c) Calculate the final velocity of the cheetah and the deer.
[2 marks]

(d) (i) Name the Physics principle that is involved in the above hunting.
....................................................................................................................................................................
[1 mark]
(ii) Define the Physics principle in (d)(i).
....................................................................................................................................................................
[1 mark]

(a) Momentum

(b) Kinetic energy

(c) (60)(20) + (70)(20) = (60 + 70)(V)
V = 17.31 m s-1

(d) (i) Principle of Conservation of Momentum
(ii) In the absence of external forces, the total momentum of a system remains unchanged

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(a) What is meant by wavelength?
....................................................................................................................................................................
[1 mark]

(b) Sound waves with frequency of 5.8 x 105 Hz are used to determine the depth of the sea. The speed of sound waves in sea water is 1250 ms-1. The time-base of the oscilloscope is adjusted at 50 ms cm-1. If the time interval between the transmitting and receiving a pulse of waves is 1.2 s. Calculate

(i) the depth of the sea. [2 marks]
(ii) the wavelength of the sound wave. [2 marks]

(c) Observe the Diagram 4.1 and 4.2.
(i) Compare the amplitude of the reflection waves.
....................................................................................................................................................................
[1 mark]
(ii) Explain your answer in (c) (i)
....................................................................................................................................................................
[1 mark]

(a) The distance between two points of the same phase.

(b)(i) d = 1250 x 0.6 = 750.0 m
(ii) f = 5.8 x 105 Hz
v = 1250 ms-1
λ = 0.00215 m / 2.15 x 10-3 m

(c)(i) The amplitude of the reflection wave in Diagram 4.2 is higher.
(ii) When the depth increases, the energy lost inceases

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(a) What is meant by density?
....................................................................................................................................................................
[1 mark]

(b) Explain why the ice block float in water.
....................................................................................................................................................................
[1 mark]

(c) What are the forces acting on the ice block?
....................................................................................................................................................................
[1 mark]

(d) Base on Diagram 5.1 and Diagram 5.2,
(i) compare the volume of water displaced.
....................................................................................................................................................................
[1 mark]

(ii) compare the weight of water displaced.
....................................................................................................................................................................
[1 mark]

(iii) Compare the buoyant force.
....................................................................................................................................................................
[1 mark]

(iv) State the relationship between buoyant force and the weight of water displaced.
....................................................................................................................................................................
[1 mark]

(v) Name the principle of physics involve.
....................................................................................................................................................................
[1 mark]

(a) Mass per unit volume

(b) Density of ice block is less than density of water

(c) Weight and buoyant force

(d) (i)The volume of water displaced in Diagram 5.1 is more than in Diagram 5.2.
(ii) The weight of water displaced in Diagram 5.1 is more than in Diagram 5.2.
(iii) Buoyant force in diagram 5.1 is greater diagram 5.2
(iv) Buoyant force = weight of water displaced
(v) Archimedes’ Principle

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(a) Name two sources where the ice cube obtained the heat to change into ice water.
....................................................................................................................................................................
[2 mark]

(b) State the change in physical state when the ice cube is melted into ice water.
....................................................................................................................................................................
[1 mark]

(c) (i) Name the physics quantity that is involved when ice cube change to water at constant temperature.
....................................................................................................................................................................
[1 mark]
(ii) Why the temperature is remain constant when ice melts to water?
....................................................................................................................................................................
[1 mark]

(d) If the amount of heat absorbed by the ice cube is 6.72 x 10³ J,
calculate the specific latent heat of fusion.
[2 marks]

(e) Why water droplets are formed on the outer surface of the metal plate?
....................................................................................................................................................................
[1 mark]

(a) Heat from the surrounding
Heat from the metal plate

(b) Solid to liquid

(c) (i) Specific latent heat of fusion
(ii) Heat absorbed is used to overcome the forces of attraction between the molecules of the ice

(d)

(e) Condensation of water vapour on cool surface

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(a) (i) Name the type of the transistor.
....................................................................................................................................................................
[1 mark]

(ii) Transistor has three terminals connected to the emitter, base and collector.
Label the emitter, base and collector in Diagram 7.1

(iii) Bulb does not light up.
No current flows in the base and emitter circuit.

(c) (i) Interchange the position of LDR and R2

(ii) (a) Because collector current is too small
(b) Magnetic relay / Relay switch
Using small voltage to switch on the second with high voltage

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(a) What is meant by electromagnet?
....................................................................................................................................................................
[1 mark]

(b) Base on Table 8, state the suitable properties of the crane to lift iron scrap more effectively.
Give reason for the suitability of the properties.
(i) Current .....................................................................................................................................................
Reason .....................................................................................................................................................
[2 mark]

(ii) Type of core .............................................................................................................................................
Reason ......................................................................................................................................................
[2 mark]

(iii) Number of turns ......................................................................................................................................
Reason .......................................................................................................................................................
[1 mark]

(c) Based on your answers in 8(b), determine the most suitable crane in
Table 8 to lift iron scrap in a factory.
....................................................................................................................................................................
[1 mark]

(d) Base on your choice in 8(c), state the change in the quantity of the iron scrap that can be lifted
when the cylindrical soft iron core is replaced with a U-shaped iron core. Explain your answer
....................................................................................................................................................................
....................................................................................................................................................................
[2 mark]

(e) A crane P is used to lift 250 kg of iron scrap to a height of 4m in 5 s.
Determine the output power of the crane P.
[2 marks]

(a) An electromagnet is a magnet in which a magnetic field is produced by the flow of electric current.

(b)(i) Increase the current.
The strength of an electromagnet increases

(ii) Soft-Iron core
Easily magnetised and demagnetised

(iii) Increase the number of turns.
The strength of an electromagnet increases

(c) L

(d) Increase // More
The poles for a U-shaped electromagnet are closer together

(e)

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(a) (i) What is meant by a refractive index? [1 mark]
(ii) Using Diagram 9.1 and Diagram 9.2, compare the refractive index, refraction angle and
critical angle between the two blocks.
Base on Diagram 9.1 and Diagram 9.2, relate the refractive index with critical angle. [5 marks]
(b) (i) State two conditions under which light ray would undergo total internal reflection. [2 marks]
(ii) Diagram 9.3 shows a light ray is incident on a piece of Crown Glass of critical angle 42°.
Draw the light ray to show how a ray emerging from the Crown Glass.

(a)(i) Ratio sin of incidence angle and sine of refraction angle
(ii) Refractive index digram9.2 larger than diagram 9.1
Refraction angle diagram 9.2 is smaller than diagram 9.1
Critical angle diagram 9.1 larger than diagram 9.2
When the refractive index is large, the critical angle is small

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(ii) Draw a circuit diagram for each circuit and label the type of circuit. [4 marks]

(b) Using Diagram 10.1 and 10.2, compare the brightness of the bulbs.
Relate the brightness of the bulb, the potential different and the current flow for
the bulbs to deduce a relevant physics concept.
[5 marks]

(c) Diagram 10.3 shows an electric kettle which is a rated at 240 V, 2 000 W and
connected by a flexible cable to a three-pin-plug.

(a) (i) Work done in moving one coulomb of charge from one point to another
(ii)

(b) 1. The bulb in parallel circuit // Diagram 10.2 is brighter than those in
series circuit // Diagram 10.1
2. The potential difference across each bulb in the parallel circuit is the
same as that of the battery // dry cell.
3. The potential difference across each bulb in the series circuit is smaller
than that of the battery // dry cell.
4. The current flowing through each bulb in the parallel circuit is higher
than the current flowing in the series circuit.
5. When the potential difference across each bulb is higher, the current
flowing through it is also higher and the bulb is brighter.
(c)

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(a) Degree of hotness of an object

(b) 1. Put the thermometer in melting ice , mark the lower part of
mercury thread,l¬0
2. Place the same thermometer in the boiling water, mark the top part
of the mercury thread, l 100
3. Divide the length between the two marks inti 100 equal divisions
4. Each division is now equal to 1 o C

(c)

(d)(i) Q = mcθ
= 0.5 x 450 x 10
= 2250 J

(ii) Energy lost = 10 x 2250 = 22500 J

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12. Diagram 12.1 shows the Dead Sea Scrolls aged 1900 years old.
An archaeologist used radioisotope to estimate age of the ancient artefact.

 (a) (i) What is meant by radioisotope?
[1 mark]

(ii) Carbon-14 is a radioisotope. Explain how Carbon-14 can be used to
estimate the age of a dead plant, which contain carbon.
[3 marks]

(b) (i) Table 12.2 shows the characteristics of the five radioisotopes, P, Q, R, and T,
that can be used to detect the brain tumour.

As a medical officer, you are required to determine the most suitable radioisotope
that could be used to inject into the blood of a patient to detect the location of a brain tumour.
Study the characteristics of all five radioisotopes based on the following aspects:
- The Half-life
- The ionising power
- The radioactive radiation

Explain the suitability of the aspects. Justify your choice.
[8 marks]

(ii) Name the most suitable detector can be used to detect the radioactive radiation from the
body of the patient. Give your reason.
[3 marks]

(c) In a nuclear reactor, 3.5 x 10-6 g of Uranium is change into energy in 1.5 ms.
Given that the velocity of light, c = 3 x 108 ms-1.
Calculate
(i) the total energy released.
(ii) the power generated by this reaction.
[5 marks]

(a) (i) Radioisotopes are isotopes which have unstable nuclei.

(ii) – Carbon-14 atom is a radioactive substance which is easily
absorbed by living plants.

- after the plants dies, the activity of Carbon-14 will decline
since no new carbon-14 is absorbed.

- by calculating the activity of carbon-14, the age of the
fossil/object can be determined

(b) (i)

Substance R is the most suitable with short half-life, emits gamma ray and
has moderate ionising power.

(ii) Geiger Muller Tube
• Has a small in size, it is handy and can be moved around easily.
• It is a sensitive instrument, so can detect low ionisation

TIMES : SPM2009 Last Minute Tips - Physics

Physics

SPM Physics is made up of Paper 1 (50 objective questions) – 1 hour 15 minutes, Paper 2 (subjective questions) and Paper 3 (written practical paper). Follow this guide to answer the papers.

Content
1. Strategy to Answering Paper 1
2. Strategy to Answering Paper 2
Section A
Section B
Section C
3. Strategy to Answering Paper 3
1. Strategy to Answering Paper 1
Paper 1 consists of 50 objective questions. Answer all the 50 questions in this paper.
The time for this Paper 1 is 1 hour 15 minutes. The average time to answer one question is one and a half minutes.
Each objective question may have three, four or five options as follows:
A, B or C
A, B, C, or D
A, B, C, D or E

Majority of them are four options. Five options are usually reserved for questions which involve calculations.
To tackle difficult questions, eliminate incorrect options one by one until you are left with the best possible option.
Know the purpose of every step in the experiments you carried out in the laboratory. Many of the questions are related to the experiments, so make sure you study the:
manipulated variable
responding variable, and
the fixed variable in the particular experiment.
Study every topic well enough. The objective questions in Paper 1 involve all the topics in the Physics syllabus.
Make sure you know the meaning of the symbols used in the formulae of SPM Physics.
Read each question diligently to understand the requirement of the question. If information such as diagrams, graphs, or data is provided, make sure you interpret them to come up with your conclusions.
Do not take more than one and a half minutes to answer each question. If you happen upon a difficult question, leave it first. Come back later to that question after you have answered all the others.
2. Strategy to Answering Paper 2
Section A
Section A consists of eight structure questions. Answer all the eight questions in this section.
The marks allocated for this section is 60 marks. Each question can carry from 4 to 12 marks.
Try to spend only 90 minutes in this section so you can have sufficient time to answer Section B and C.
Study the diagrams, tables, graphs or data provided carefully before attempting to answer the question. They are usually related to a certain situation or phenomenon.
Highlight key words provided so that you will not go out of point in your answers.
Note the marks allocated to each section of a question. A section allocated 1 mark will only require a short answer. A section allocated 3 marks will require you to state 3 properties or characteristics associated with the section.
When answering questions involving calculations, write down the complete steps and the formula used in the spaces provided. This will allow the examiner to study your approach. If you make a careless mistake in a sub-section, follow through marks may still be given for other sub-sections that are correctly done.

Section B
Section B consists of two questions. Answer only one question from this section.
The marks allocated for this section is 20 marks.
You are advised to spend 30 minutes on this section.
The questions from Section B are normally preceded by a diagram that shows a certain state or situation that is related to a specific Physics concept.
You are normally asked to state the characteristics shown in the diagram and also to state the Physics principle involved.
Study the marks allocated to each section or sub-section in the question. The marks allocated in each section can be as high as 10 marks. In such cases, make sure that you have at least 10 points or properties related to the section. Each point is normally allocated 1 mark.
Give your answers clearly and logically. Equations, diagrams, tables, graphs or other suitable methods may be used to explain your answer.

Section C
Section C consists of two questions. Answer only one question from this section.
The marks allocated for this section is 20 marks. You are advised to spend 30 minutes on this section.
Questions in this section normally require the interpretation of the data provided.
The questions from Section C are normally preceded by a table that is related to a specific Physics concept.
You may be required to plot a graph based on the data given. Make sure that you know the proper steps to plot a graph.
Study the marks allocated to each section or sub-section in the question. The marks allocated in each section may be as high as 10 marks. In such cases, make sure that you have at least 10 points or properties related to the section as each point is normally allocated 1 mark.
The questions in this section normally require you to state a certain principle or to explain certain properties or characteristics based on the information given.
Note that questions in Section B and C only involve the explanation of theories and do not contain questions that require you to do describe an experiment.
3. Strategy to Answering Paper 3
Section A
Section A consists of two structured questions. Answer both of the questions.
The total marks for this section is 28 marks. You are advised to spend 60 minutes on this section.
The questions in this section are based on experiments that you should have already done in the laboratory.
The questions in this section normally require you to collect and tabulate the data in a table and to plot a graph.
You are normally required to state the manipulated variable, the responding variable and the fixed variable based on the aim and procedure of the experiment.
The questions from this section may also involve the interpretation of graphs. You need to carefully determine the quantity represented by the slope of the graph. You will also need to know how to determine the slope of the graph.
The questions from this section may involve the calculation of certain quantities. Make sure that you write down all the steps involved in the spaces provided.

Section B
Section B consists of two questions. Answer one question only.
The total marks for this section is 12 marks. You are advised to spend 30 minutes on this section.
The questions in this section are normally preceded by a diagram depicting a situation in our daily lives together with a brief write-up on the situation shown.
Study the situation carefully. You are normally asked to state one suitable inference that can be made from the situation.
Make sure you provide a fully labeled diagram of the apparatus used. Write out your experiment in passive form and use short sentences.
When making a conclusion, make sure that your conclusion is in line with your hypothesis.

SOALAN RAMALAN PERCUBAAN SPM 2009

Fizik Percubaan SPM 2009

Kertas 2

Bahagian A
1. Alat pengukuran dan ralat
2. Gerakan linear, halaju, pecutan dan pita detik
3. Tranformer dan litar eletrik
4. Termometer
5. Pembiasan, pantulan dalam penuh
6. Daya-daya paduan
7. Get-get logik
8. Prinsip Bernoulli

Bahagian B
9. Inersia
10. Gelombang, interferen dan panjang gelombang
Bahagian C

11. Radioaktif dan isotop dan kegunaan radiaoaktif dalam industri
12. Muatan haba tentu dan haba pendam tentu

Kertas 3

Bahagian A
1. Prinsip Archemedes
2. Pemanjangan spring dengan hukum Hooke

Bahagian B
3. Hubungan tekanan cecair dengan kedalaman yang berlainan
4. Hubungan jarak objek dengan jarak imej kanta cembung


Kimia Percubaan 2009

KERTAS 2

BAHAGIAN A
1. Tindak balas penyesaran.
2. Jadual berkala dengan nombor atom dan isotop / susunan elektron.
3. Hidrokarbon alkena dan alkana.
4. Proses Sentuh.
5. Tindak balas kalsium karbonat dengan asid.
6. Lemak dan minyak.

BAHAGIAN B
1. Proses Haber atau penyulingan Petroleum.
2. Penghasilan getah.

BAHAGIAN C
1. Mencari formula empirik.
2. Proses elektrolisis.

KERTAS 3
1. Takat lebur dan takat didih.
2. Sel kimia.
3. Eksperimen kereaktifan logam terhadap oksigen.


Biologi Percubaan SPM 2009

Kertas II

Bahagian A
1. Struktur dan fungsi sel haiwan
2. Kepekatan larutan (hipotonik / isotonik / hipertonik)
3. Enzim
4. Koordinasi saraf dan kimia
5. Meiosis

Bahagian B
1. Respirasi sel
2. Sistem peredaran darah manusia dan haiwan dan sistem pertahanan badan

Bahagian C
3. Nutrisi tumbuhan
4. Hukum Mendel

Kertas III
1. Variasi
2. Peranan mikroorganisma


SAINS Percubaan SPM 2009

KERTAS II
Bahagian A
1. Jadual berkala serta isotop.
2. Fungsi neuron dan tindakan refleks.
3. Variasi, anak kembar dan penyakit baka dan penentuan seks anak.
4. Penapis warna dan penambahan warna.

Bahagian B
5. Tindakbalas peneutralan.
6. pempolimeran dan pendepolimeran.
7. Keadaan yang sesuai untuk pertumbuhan mikroorganisma dan penyakit serta keimunan.
8. Pengekstrakan logam dan tindakbalas berkaitan dengan cahaya.
9. Momentum dan inersia.

Bahagian C
10. Elektrolisis dan kegunaanya.
11. Kanta, mata dan alatan optik.
12. Tekanan hidrolik / masalah pencemaran

KERTAS I (50 Soalan Objektif)
Tingkatan 4
Bab 1. Tiada
2. Jenis-jenis bahan , aloi, keadaan jirim.
3. Otak, kelenjar endokrin, penyalahgunaan dadah.
4. Pembahagian sel meosis mitosis, variasi
5. Keradioaktifan dan jenis-jenis sinaran.
6. Sel ringkas, fotosintesisi.
7. Mata, kamera, pergerakan atau penyebaran cahaya, penambahan dan penolakan warna.
8. Aloi, ammonia.
Tingkatan 5
Bab 9. Jenis-jenis mikroornagisma, pengimunan.
10. Perbezaan hidrokarbon tepu dan tak tepu, getah petrokeum.
11. Kelas makanan, nialai kalori makanan dan masalah kesihatan.
12. Prinsip Archinedes dan Bernouli, satelit dan enjin.
13. Rantai makanan, langkah mengawal pencemaran..
14. Cara memproses makanan, kitar nitrogen, akta makanan.
15. Jenis-jenis plastik
16. Pemancar radio dan satelit.


Matematik Percubaan SPM 2009

Kertas II

Bahagian A

1. Ungkapan kuadratik - pemfaktoran
2. Persamaan serentak - penyelesaian menggunakan kaedah penghapusan ataupun
kaedah matriks
3. Ketaksamaan linear (menggunakan graf untuk membuat lorekan)
4. Garis dalam 3 matra (mesti tahu menggunakan kosinus, sinus & tangen)
– antara garis dengan satah
5. Garis lurus - kecerunan (mesti tahu maksud ‘selari = kecerunan sama’ serta
pintasan-x & pintasan-y)
6. Isipadu janaan - isipadu prisma
7. Panjang lengkok, perimeter dan luas
- mencari penjang lengkok, mencari luas sector

Bahagian B
1. Graf fungsi - kuadratik
- kubik
- salingan


BAHASA MELAYU Percubaan SPM 2009

KERTAS I
Bahagian A - Karangan bergambar – Amalan budi
bahasa / rumah terbuka

Bahagian B
1. Peranan telekomunikasi
2. Kepentingan sungai
3. Sumbangan pekerja asing
4. Keruntuhan akhlak remaja
5. Cara mengukuhkan sukan negara

KERTAS II
2a) Rumusan
2b) Cerpen – Annyss Sophiea / Di sisi rinda
2c) Prosa Klasik – Sabor pertaruhan Hang Tuah dan Hang
Jehat.
2d) Puisi – Sajak keindahan yang hilang atau pantun
menyerang nasib
3) Tatabahasa
4) Novel – Gaya bahasa / latar

*Diambil dari sumber internet (belum dikenal pasti kesahihan)
*Percubaan JPN atau YIK (tidak pasti)

TAJUK FOKUS FIZIK KERTAS 2 SPM 2009

1. Ammeter/ voltmeter
2. Bernoulli’s Principle
3. Reflection of wave
4. Archimedes’ Principle
5. Lift, a=0, a up, a down
6. Transistor
7. Len’s Equation
8. E=mc2
9. Impulsive force
10. Electriacal circuits
11. Heat
12. Transformer

Reflection and Refraction

Reflection

Waves (and in particular light) is reflected off of surfaces. If we take the example of rays of light on a mirror, a virtual image is formed. This is upright, the same size, and appears to be directly behind the mirror.

If a ray of light is beamed at a mirror, this will be reflected. The normal to the block is perpendicular to it, the angles are measured in reference to this. The ray going in is called the incident ray and the acute (smaller) angle it makes with the normal is called the angle of incidence. See diagram below to understand this.


The angle the reflected ray leaves is equal to the angle of incidence. I.e. angle of incidence = angle of reflection.


Refraction

Refraction has light waves changing direction. This occurs as a result of the light changing speed when it goes from one medium to another. The speed of light varies according to what it is travelling through, the standard given is the speed in a vacuum, this is 299 792 Km/s, the speed of light in water is 225 000 Km/s.

Take a look at the example of refraction shown below. The light ray is travelling through tank of water.



When the light enters the water, it slows down so moves towards the normal. When the light emerges from the tank into air, it speeds up so it moves away from the normal.

Refraction in water is the reason that when you stand beside a swimming pool and look down at it, it appears to be shallower than it really is. Also, if you put a straw at an angle in a cup of water (or juice or whatever), it will appear to bend at the water-air boundary.

Total Internal Reflection (TIR)

The inner surface of a glass block will begin acting like a mirror if a ray of light strikes it at the critical angle, this is 42°. This value is less in other mediums, for instance it is 49° between water and air.

When the angle of incidence is equal to the critical angle, the light will emerge along the edge of the block, but when the angle of incidence is more than the critical angle, it will be reflected. The diagram below illustrates this.



This phenomenon is put into practical use in fibre optic cables. Where light signals will travel along a glass fibre providing the angle of incidence exceeds the critical angle of 42°. Fibre optic cables are used to send telecommunication information such as the internet.

Sound

Sound Waves

Sound waves are longitudinal waves and can be reflected, refracted and diffracted like all waves. They are mechanical vibrations of particles that can be detected by the human ear.

When a sound wave is reflected we call it an echo. Echoes of ultrasound are used by bats and sonar, to detect the position of things.

A sound wave can be represented as a sine curve; by altering its amplitude and frequency, we can change the sound.



If the amplitude is increased, the sound gets lounder - so a higher volume. If the frequency is increased, you get a higher pitched sound. Humans can only hear sounds that are in a certain range of frequencies, this is generally 20 to 20 000 Hz, but perception of sounds at the upper end reduced with age. Sounds that are above 20 000Hz are said to be ultrasonic.

Ultrasound

Humans can hear within the 20 to 20 000Hz range. Other animals have much higher ranges of hearing: dogs can hear up to 45 000 Hz, cats up to 64 000Hz and the bat up to 110 000 Hz. Some animals also have ranges of hearing much smaller than humans: the chicken has a range of 125 - 2000Hz.

Ultrasound has many uses, and here we will look at SONAR and medical imaging.

Sonar stands for 'sound navigation and ranging'. In it's simplest form, it can be used to calculate the depth of the sea. This is done by emitting an ultrasonic pulse, this bounces off of the sea bed as an echo, and the time taken for it to return is recorded. Using, speed = distance/time it is possible to calculate the distance, take the example below.

Properties of Waves

A Wave


Amplitude is the height of the wave from 0 displacement (normal) to the peak, where the peak is the highest point. The Wavelength is the distance from the start to the second point the wave passes 0. i.e. a complete wave.

Period: if it was a displacement/time graph, the period would be equivalent to wavelength, so period is the time for the wavelength. The frequency is 1 / period and measured in Hz (1Hz = 1wave per second)

The Wave Equation




Transverse


The oscillation/vibration is at right angles to the direction of travel. An example of transverse waves are electromagnetic waves

Longitudinal Wave


The oscillations/vibrations are along the line of travel.
Are mechanical waves because it actually moves particles. E.g. sound waves.