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Thursday, March 29, 2012

Moral dan Motivasi Pelajar

7 Langkah Mencapai Matlamat


"Orang yang berjaya dalam hidup adalah orang yang nampak tujuannya dengan jelas dan menjurus kepadanya tanpa menyimpang." - Cecil B. DeMille

Artikel motivasi ini menjelaskan langkah-langkah, cara-cara, kaedah-kaedah, strategi-strategi, teknik-teknik, tip-tip, panduan-panduan atau rahsia-rahsia mencapai matlamat dan kejayaan yang anda inginkan.
Untuk mencapai matlamat anda dan berjaya dalam kehidupan, anda mestilah membina suatu kebiasaan berdasarkan langkah-langkah yang telah terbukti keberkesanannya seperti berikut:

1. Wujudkan Keinginan Anda Sebesar Mungkin
Keinginan tersebut mestilah yang benar-benar anda idamkan. Bagaimana menyemarakkan keinginan anda? Duduk dan tulis semua keinginan anda. Nyatakan faedah-faedah dan kebaikan-kebaikan mencapai segala keinginan anda itu. Fikir dan tulislah sepuas-puasnya. Apabila senarai anda menjangkau 50 hingga 100, suatu bentuk perasaan atau semangat pada diri anda akan timbul. Teruskan. Anda akan mula menjadi lebih bersemangat. Jika anda terus menulis dan menghayati segala matlamat anda itu, semangat anda akan bertambah menyala, berapi-api! InsyaAllah.

2. Tuliskan Matlamat-Matlamat Anda
TULIS matlamat-matlamat anda di atas sehelai kertas. Jika anda tidak tulis, ia hanya akan menjadi angan-angan sahaja. Salinkannya ke dalam Buku Matlamat anda. Ini PENTING, kerana dengan berbuat demikian, ia akan menjadi perkara yang penting bagi anda. Dengan berbuat demikian juga, ia akan mula meresap ke dalam minda separa sedar anda.

3. Tetapkan Tempoh dan Bila Anda Akan Mencapai Matlamat Anda
Kaji tahap atau kedudukan anda sekarang berbanding dengan apa yang anda inginkan. Kira dan tentukan berapa banyak masa yang anda perlukan untuk mencapai matlamat anda itu. TETAPKAN bila matlamat tersebut mesti anda capai.

4. Buat Perancangan
RANCANGKAN tindakan-tindakan anda. Senaraikan semua aktiviti mengikut susunan keutamaannya. Perbaiki senarai anda; optimumkannya, sempurnakannya.

5. Gambarkan Kejayaan Pada Minda Anda
Letakkan suatu Studio Filem di minda anda! Bayangkan satu GAMBARAN MENTAL yang anda telah berjaya mencapainya. Buat imej minda yang jelas dan terang pada mata minda anda. Mainkan gambaran itu berulang-ulang – berkali-kali di fikiran anda. Ingatlah bahawa: "Orang yang berjaya dalam hidup adalah orang yang nampak tujuannya dengan jelas dan menjurus kepadanya tanpa menyimpang." - Cecil B. DeMille. Ingatlah juga kata Mahatma Gandhi: Seseorang itu

6. Tangani Halangan
1) Kenalpastikan halangan-halangan yang perlu anda atasi.
2) Tumpukan kepada usaha mendapat bantuan; bantuan yang anda akan perlukan untuk mencapai matlamat anda - misalnya pengetahuan, pakar-pakar, penasihat-penasihat atau badan-badan tertentu. adalah hasil dari fikirannya. Apa yang dia fikir, itulah yang dia akan menjadi".

7. Baki 90% Adalah Usaha dan Keazaman Anda
Sokong rancangan anda dengan KEAZAMAN (Resolve) dan SEMANGAT TIDAK MENGENAL PUTUS ASA (Persistence). Tekadkan semangat. Tumpukan kepada kejayaan. Fokuskan segala perhatian dan tenaga anda untuk mencapai segala matlamat anda pada waktu yang anda sendiri tetapkan. Bulatkan hati dan fikiran. Jangan sekali-kali berputus asa terhadap sebarang cabaran. Lakukanlah tindakan-tindakan proaktif dan produktif.

Insya-Allah, dengan diiringi doa, keazaman, disiplin yang tinggi serta usaha gigih, anda akan mencapai apa juga matlamat yang anda ingini dan impikan.

petikan dari Taidin Suhaimi

Wednesday, March 28, 2012

Why do rainbows appear? What are the differences between primary rainbow and secondary rainbow?


White sunlight actually contains a wide variety of colors, which may be roughly classified as seven colors, namely, red, orange, yellow, green, blue, indigo and violet. Normally, we see the sun in white color. After rain, there are still some tiny water droplets remained in the air. If there is sunshine a white sunbeam will be reflected and refracted by these tiny droplets. Different colors of light have different refractivity. They will be reflected in slightly different directions inside a water droplet. If we observe the sky from different angles of elevation, we will see different water droplets reflecting out different colors of light. A rainbow is formed (Fig. 1).

Both the primary and secondary rainbows are phenomena that formed by the reflection and refraction of sunlight in tiny water droplets. When a sunbeam is being refracted twice and reflected once by the droplet, a primary rainbow will form (Fig. 2 a). If the beam is being refracted twice and reflected twice, a secondary rainbow will form (Fig. 2 b). As the secondary rainbow is formed by one more reflection than the primary rainbow, it is much fainter and rare to see. On the other hand, since the paths of sunbeams in a primary rainbow and a secondary rainbow are different, the colors of the secondary rainbow are arranged in just the reverse order of the primary one (compare Fig. 2 a and 2 b).
Refraction and reflection of light by a water dropletFormation of primary rainbowFormation of secondary rainbow

What is a mirage? How is it formed?


Fig. 1  In regions of air with temperature decreases with altitude, light will travel in a curved path due to refraction.
Fig. 2  Refraction occurs when a light beam travels from glass to the air. The angle of incidence i is smaller than the angle of refraction r.
Fig. 3  Total internal reflection occurs when the incident angle i is larger than the critical angle c.
Fig. 4   The path of light when a mirage happens.
A traveler has lost his way in the desert. Enduring thirst and hunger, he suddenly saw an oasis, so the overjoyed man quickly ran towards it. To his great disappointment, it was just an illusion produced by a mirage. Such an episode was often pictured in movies, yet the optical magic that the nature plays with us - mirage - really exists in reality. Its formation is a result of the refraction and the total internal reflection of light in the air. 

To investigate the formation of a mirage, we firstly need to understand why light is refracted in the air. Regions of air at different temperatures have different refractive indexes, just like many different mediums. The closer the air is to the ground, the hotter it will be, and its refractive index will be smaller. We could imagine the air as many layers of medium with a particular refractive index for every layer, and the refractive index is smaller for those that are closer to the ground. Thus when light travels in air, its path is as shown in Fig.1. 

On the other hand, we should also understand what total internal reflection is. If light travels from glass to the air with a small incident angle, part of the light will be reflected back while the remaining part will be refracted, passing out from the glass. As the refractive index of glass is larger than that of the air, the refracted angle is always larger than the incident angle (Fig. 2). When the incident angle becomes larger, the refracted light will get closer and closer to the interface between the air and the glass. When it is larger than the critical angle, the light will only be reflected but not refracted. This phenomenon is called total internal reflection (Fig. 3). 

Fig. 4 shows the path of light when a mirage happens. Suppose there is an oasis and the light it emits at point A is refracted by the air, the light will travel through a curved path. Total internal reflection occurs at point B and will cause the light to travel upwards. Then the light is refracted by the air again. At last, it will enter the eyes of the observer at point C, producing an illusion that the oasis is close to him. 

Total internal reflection has been discovered for a long time already. Some of its broad applications include optical fibre, single lens reflex camera and binocular telescope.

Why do sound waves transmit farther at night? Is it because it is quieter at night?

If you go to the beach on vacation, during the night, you will discover that voice of people far away can be heard clearly. You may wonder, it is because it is quieter at night than in the daytime. Therefore it is easy to hear the sound far away. However, it is only one of the reasons. Actually, sound transmits farther at night may be related to refraction of sound waves! First, sound is the vibration of air, and it is a kind of wave motion. The propagation of sound wave is faster in hot air and slower in cold air. Therefore regions of air at different temperatures have different refractive indices, just like media with different optical densities. When sound wave propagates in air whose temperature changes with altitude, refraction of air happens. Sound will move towards areas with lower temperatures. In the daytime, when the sun shines the earth, the air near the earth surface is hotter than the air above. Sound waves will be refracted to the sky (Fig. 1). On the contrary, in the nighttime, the air near the surface is cooler and sound waves are refracted to the earth surface (Fig. 2).

Sound waves will be refracted to the sky in the daytimeSound waves will be refracted to the ground in the nighttime

What is lightning? How does lightning happen?

Scientists have not fully understood the mechanism of lightning. We can describe the process of lightning, but many phenomena of lightning have not been explained. According to observation, the upper part of a cloud carries positive charge, while the lower part carries negative charge, therefore the ground is induced with a large amount of positive charge. The potential at the bottom of the cloud is much lower than that of the ground, therefore negative charge will be accelerated towards the ground. When lightning begins, a "step leader" comes from the cloud to the ground. The step leader is not very bright, but it propagates at a high speed. First, it propagates for about 50 m, stops for a while, then proceeds in a different direction, and stops again. The process repeats many times, making a zigzag path filled with negative charge. High speed electrons ionize air, thus providing a conducting path for the stoke. When the step leader comes close to the ground, a strong electric field is created, which drives the positive charge on the ground to neutralize the negative charge in the path. The discharge releases an enormous amount of energy, and it is called the "returning stoke". The returning stoke is much brighter than the step leader, so what we see at lightning is a discharge which actually goes from the ground to the cloud! The returning stoke is the origin of the strong light, heat and sound in lightning. 

The step leader 
The returning stroke
Fig. 2  The formation of the returning stroke.
 

Tuesday, March 27, 2012

Principle of Van de Graff

Van de Graff Generator
It is based on the following principles:
1) Action of sharp points: Charges are leaked from pointed ends of charged conductors. This creates an electric wind (as moving air is ionized) which moves away from the conductor.
2) The property that the charge given to a hollow conductor is transferred to the outer surface and is distributed uniformly on it.
The straightforward principle behind the Van der Graaf generator is as follows. Electric charges of the same type (either positive or negative) are put onto a moving belt, carried upwards by the belt into a hollow copper dome, and left there. This is a continuous process, the belt collecting charge at the bottom and depositing for storage at the top. As the amount of charge on the dome builds up, its voltage increases.

Suppose the dome is to be negatively charged. At the lower end of the machine is an electric generator capable of making a direct current of electricity at a relatively low voltage – about 20,000 volts. To the negative terminal of this generator are attached a number of sharp metal spikes, which of course become negatively charged. They are fixed a short distance away from the moving belt.

The charges on the spikes are so densely packed that they are pushed off by fresh charges arriving from the generator. These jettisoned charges are carried by moving air molecules towards the belt which is in effect "sprayed" with negative charges.

The belt is made from an insulating material – rubber, silk, or linen – so that the charges stay fixed on the belt as it moves upwards.

At the top of the Van der Graaff generator is another set of metal spikes, attached to the inside of the dome. The negative charges on the moving belt repel negative charges (which previously formed the outer parts of metal atoms in the spikes) to the dome. The positive charges left on the spikes are "sprayed" onto the belt where they neutralize the negative charges brought up by the belt. The negative charges repelled from the spikes to the dome fly to the outside of the dome. There is no charge on the inside surface of the dome, so there is nothing to prevent further negative charges coming to it from the spikes.

Van der Graaff generator charge
Left: charging negatively. Right, charging positively
When the voltage difference between the dome and the Earth is a few million volts, it becomes very difficult for the dome to hold its charge. Charges, closely crowded together on the outer surface, repel each other and start to leak away into the surrounding air, or else flow, in a gigantic spark, to Earth. To prevent this, the dome is highly polished so that there are no bumps where denser patches of charge can accumulate. The entire generator is placed in a steel enclosure filled with gas (sulfur hexafluoride or nitrogen) at high pressure. It is more difficult for the charge to leak through high-pressure gas than through ordinary air.

The Van der Graaff machine is used to accelerate streams of particles, so that they move quickly enough to produce interesting effects when they hit target atoms. The particles are initially stationary at the top of a long tube reaching from the top of the tube to the ground. When the dome is connected to the top of the tube, an enormous voltage accelerates the electrically charged particles towards the bottom of the tube. Usually the machine accelerates streams of positively charged particles, and the dome must be positively charged to repel the positive charges. To charge the dome positively, the lower spikes are attached to the positive terminal of the 20,000-volt generator.

Van de Graff Generator

Operation of a Van de Graaff generator

How does a Van de Graaff generator operate?

Van de Graaff generator was invented by the American scientist Robert J. Van de Graaff (1901- 1967) in 1931. Based on the principle of charging by friction, the generator can produce a large amount of charge. The figure shows the model commonly used in schools. It contains a rubber belt set into motion by a plastic roller. Static electricity is generated by the friction or by a high voltage at a pointed electrode (Fig. 1). The rolling rubber belt then carries the charge to the inner surface of the spherical metal cover. Due to mutual repulsion, the charge is repelled to the outer surface of the spherical cover, and hence a large amount of charge will accumulate there.

What are the applications of the generator?

Van de Graaff generator can produce a voltage of over 10 million volts on its spherical cover. In nuclear physics, such a high voltage can be used to accelerate various kinds of charged particles, like protons, electrons etc. Moreover, the generator can be used to demonstrate many interesting phenomena of static electricity. For examples, it can make your hair stand upright, attract a metal ball (Fig. 2) or a polystyrene ball, produce an electric spark, and generate electric wind to set a mini-windmill into rotation. Through these phenomena, we can understand more about the nature of static electricity.

Making hair stand upright

We can stand on an insulated chair, and put our hands the spherical metal cover of the generator. Since human body can conduct electricity, charge will be transferred to our body when the generator begins to operate; and because of the mutual repulsion of charge, the hair will stand upright.

Attracting a polystyrene ball

When a polystyrene ball is placed close to the generator, the charges inside the molecules of the ball will be redistributed. In a molecule, the positive and the negative charges will be slightly separated, producing the phenomenon of polarization. In this case the charge on the spherical cover will produce a slight attractive force on the opposite charges in the molecules, and hence the whole polystyrene ball will be attracted.

Producing electric spark

When a small grounded metal ball is placed close to the spherical cover of the generator, the strong electric field will cause the charge to leap towards the ball, producing a large amount of ions and electrons in air. Since the energy of the ions are higher than that of the neutral molecules, they will release their energy spontaneously and produce a spark, which is a discharge in air. Lightning, for example, is a discharge phenomenon in which charge leaps from a cloud to another or to the ground.

Producing electric wind

A sharp point on a charged conductor has a higher surface charge density which will generate a stronger electric field. The strong electric field ionizes the air molecules surrounding the sharp point, and those ions or electrons which have charge opposite to that of the conductor will be attracted towards the sharp point, while those ions or electrons with the same charge will be repelled. This phenomenon is called the point effect. The moving ions drag air molecules into motion, producing an electric wind that can turn a mini-windmill.

Applications of static electricity in daily life

The are many applications of static electricity in daily life, including photocopying, electrostatic precipitator and electrostatic spraying. Besides, knowing more about static electricity can help us to prevent possible hazards. For example, a vehicle carrying inflammable materials has an iron chain attached to its rear; this transfers charge to the ground to prevent fire caused by sparks. For the same reason, since oxygen and inflammable anaesthetic are often used in a hospital, the floor of an operating room is usually anti-static, and all the instruments have to be grounded. This prevents explosion caused by sparks.

Van de Graff

Schematic view of a classical Van de Graff-generator.
1) hollow metal sphere
2) upper electrode
3) upper roller (metal)
4) side of the belt with positive charges
5) opposite side of the belt with negative charges
6) lower roller (for example an acrylic glass)
7) lower electrode (ground)
8) spherical device with negative charges, used to discharge the main sphere
9) spark produced by the difference of potentials

A simple Van de Graaff-generator consists of a belt of silk, or a similar flexible dielectricmaterial, running over two metal pulleys, one of which is surrounded by a hollow metal sphere.[1] Two electrodes, (2) and (7), in the form of comb-shaped rows of sharp metal points, are positioned respectively near to the bottom of the lower pulley and inside the sphere, over the upper pulley. Comb (2) is connected to the sphere, and comb (7) to the ground. A high DC potential (with respect to earth) is applied to roller (3); a positive potential in this example.
As the belt passes in front of the lower comb, it receives negative charge that escapes from its points due to the influence of the electric field around the lower pulley, which ionizes the air at the points. As the belt touches the upper roller (6), it transfers some electrons, leaving the roller with a negative charge (if it is insulated from the terminal), which added to the negative charge in the belt generates enough electric field to ionize the air at the points of the upper comb. Electrons then leak from the belt to the upper comb and to the terminal, leaving the belt positively charged as it returns down and the terminal negatively charged. The sphere shields the upper roller and comb from the electric field generated by charges that accumulate at the outer surface of it, causing the discharge and change of polarity of the belt at the upper roller to occur practically as if the terminal were grounded. As the belt continues to move, a constant charging current travels via the belt, and the sphere continues to accumulate negative charge until the rate that charge is being lost (through leakage and corona discharges) equals the charging current. The larger the sphere and the farther it is from ground, the higher will be its final potential.
Another method for building Van de Graaff generators is to use the triboelectric effect. The friction between the belt and the rollers, one of them now made of insulating material, or both made with insulating materials at different positions on the triboelectric scale, one above and other below the material of the belt, charges the rollers with opposite polarities. The strong e-field from the rollers then induces a corona discharge at the tips of the pointed comb electrodes. The electrodes then "spray" a charge onto the belt which is opposite in polarity to the charge on the rollers. The remaining operation is otherwise the same as the voltage-injecting version above. This type of generator is easier to build for science fair or homemade projects, since it doesn't require a potentially dangerous high voltage source. The trade-off is that it cannot build up as high a voltage as the other type, that cannot also be easily regulated, and operation may become difficult under humid conditions (which can severely reduce triboelectric effects). Finally, since the position of the rollers can be reversed, the accumulated charge on the hollow metal sphere can either be positive or negative.
A Van de Graaff generator terminal doesn't need to be sphere shaped in order to work, and in fact the optimum shape is a sphere with an inward curve around the hole where the belt enters. Since electrically charged conductors have no e-field inside, charges can be added continuously. A rounded terminal minimizes the electric field around it, allowing greater potentials to be achieved without ionization of the surrounding air, or other dielectric gas. Outside the sphere the e-field quickly becomes very strong and applying charges from the outside would soon be prevented by the field.

Health Alert-Flu

Influenza atau flu adalah penyakit berjangkit disebabkan oleh virus influenza.

Virus influenza

Terdapat 3 jenis virus influenza iaitu A, B dan C. Ketiga-tiga ini boleh menjangkiti manusia. Virus influenza A adalah paling berbahaya kerana boleh menjangkiti haiwan dan manusia. Virus influenza A boleh menjalani mutasi (perubahan genetik) dan menghasilkan virus influenza jenis baru dan lebih berbahaya. Ini akan mencetuskan kejadian epidemik dan pandemik influenza.


Adakah influenza sama dengan demam selsema?

Tidak.

Walaupun kedua-duanya mempunyai gejala yang hampir sama tetapi influenza menyebabkan gejala dan tanda-tanda yang lebih teruk serta boleh menyebabkan komplikasi yang mengancam nyawa.

Perbandingan antara influenza dan deman selsema:

Tanda &
Gejala
Influenza
(Flu)
Demam Selsema
(Common Cold)
Demam
Tinggi. Biasanya melebihi 38°C.
Kurang dari 38°C.
Letih lesu
Teruk dan boleh berlarutan hingga 2 ke 3 minggu.
Sangat ringan.
Sakit otot / sakit sendi
Sederhana ke teruk.
Ringan.
Batuk
Batuk teruk, tidak berkahak pada peringkat awal.
Tiada / Ringan.
Hidung berair / berhingus
Tiada / Ringan.
Teruk.
Bersin
Kerap.
Tidak kerap.
Sakit tekak
Sederhana ke teruk.
Tiada / Ringan.
Sakit kepala
Sederhana ke teruk.
Ringan.
Penyebab
Virus influenza A, B atau C.
Adenovirus, rhinovirus, parainfluenza virus, corona virus dan lain-lain.


Apakah rawatan bagi influenza?

Tiada rawatan khusus untuk influenza. Rawatan yang diberikan adalah rawatan simptomatik sahaja.

Anda dinasihatkan untuk mengambil tindakan-tindakan berikut:
  • Mengambil ubat demam seperti paracetamol untuk melegakan demam dan sakit kepala.
  • Minum air atau minuman suam bagi melegakan sakit tekak dan batuk.
  • Amalkan pemakanan seimbang dan tidur atau rehat yang secukupnya.
  • Hindarkan stress kerana ini akan melemahkan sistem pertahanan badan.
  • Jika tanda dan gejala berlarutan atau tambah teruk dapatkan rawatan di klinik atau hospital.

Bagaimana jangkitan influenza boleh dielakkan dari merebak?

i) Jika anda bersin atau batuk:
  • Tutup mulut dan hidung dengan tisu atau sapu tangan.
  • Buang tisu yang digunakan ke dalam tong sampah.
  • Jangan berkongsi sapu tangan.
  • Basuh tangan dengan sabun selepas batuk dan bersin. Juga basuh tangan dengan bersih setelah menyentuh bahan mentah, permukaan tercemar, muka, hidung, telinga dan lain-lain anggota badan.
ii) Pakai penutup mulut dan hidung (mask) untuk mengelakkan jangkitan influenza.

iii) Elakkan dari berada di tempat-tempat awam jika anda dijangkiti influenza.


Apakah perbezaan antara ubat antiviral dan vaksin influenza?

Ubat antiviral adalah ubat bagi merawat pesakit yang dijangkiti virus. Pemberian ubat antiviral pada masa yang betul akan dapat mengurangkan impak gejala dan tanda penyakit serta mengurangkan kemungkinan komplikasi penyakit.

Vaksin diberi sebagai langkah pencegahan. Vaksinasi menggunakan vaksin influenza yang ada di pasaran hanya untuk memberi perlindungan kepada individu dari mendapat jangkitan.

Kementerian Kesihatan Malaysia menyarankan mereka yang akan melawat negara yang sedang mengalami musim sejuk dan mereka yang akan mengerjakan haji dan umrah di Mekah agar mendapatkan suntikan vaksin influenza. Suntikan boleh diperolehi dari klinik atau hospital swasta tertentu.


Pastikan anda dapat membezakannya!

Anda haruslah memahami dan dapat membezakan istilah-istilah yang digunakan berkaitan dengan influenza:

Avian Influenza.
Avian influenza atau selsema burung adalah sejenis penyakit berjangkit yang biasanya berlaku di kalangan ayam, itik dan burung (unggas). Ia juga boleh menjangkiti manusia.

Epidemik influenza.
Epidemik influenza adalah kejadian wabak influenza yang menyerang sekumpulan penduduk di sesuatu lokasi atau negara.

Pandemik influenza.
Pandemik influenza adalah wabak influenza yang menyerang sebahagian besar dari penduduk dunia. Ia berlaku akibat kemunculan virus influenza baru yang mana penduduk dunia tidak mempunyai daya ketahanan badan bagi melawan virus tersebut. Vaksin influenza yang sedia ada tidak dapat melindungi serangan virus pandemik influenza.

PEKA SCIENCE, PHYSICS, CHEMISTRY, BIOLOGY SPM 2012

Construct that is assessed in PEKA SPM Form 4 and 5.

* Constructs I, III and IV are assessed based on evidences of laboratory reports.
** Constructs II and V are assessed based on observations made by the teacher while conducting the PEKA experiment and also in the process of teaching and learning.

* Construct I - Planning of the experiment
  • C1P1 - State the aim of the investigation or experiment accurately.
  • C1P2 - State the hypothesis accurately.
  • C1P3 - State all the variable involved.
  • C1P4 - List down all the materials or apparatus.
  • C1P5 - Write the complete procedure or technique.

** Construct II - Carrying out the experiment (based on planning, and usage and handling of materials/apparatus)
  • C2P1 - Ability to use and handle the materials or apparatus carefully.
  • C2P2 - Ability to clean the materials or apparatus in a proper way.
  • C2P3 - Ability to store or put back the materials or apparatus correctly and safely.
  • C2P4 - Ability to sketch or draw any specimen or science apparatus arrangement correctly and accurately.

* Construct III - Collecting and recording data/observation
  • C3P1 - Able to construct a table with the correct manipulated and responding variables.
  • C3P2 -Able to complete the manipulated variable data in the table correctly.
  • C3P3 - Able to record the data/observation of the responding variable obtained from the experiment correctly.

* Construct IV - Interpreting data and making conclusions
  • C4P1 - Able to interpret data or discuss or plot a graph correctly:
    (i) Title of the graph.
    (ii) Axes that are labelled with the correct units.
    (iii) Uniform scale.
    (iv) Correct graph for the experiment.

  • C4P2 - Able to state whether the hypothesis is accepted or rejected.

  • C4P3 - Able to make a correct conclusion/summary of the experiment.


** Construct V - Scientific attitudes and noble values
  • C5P1 - Show inquisitiveness and interest.
    (i) Frequently asking the teacher or friends questions related to the task.
    (ii) Always ready to accept other people's ideas and opinion.
    (iii) Keen in all the task given.

  • C5P2 - Systematic attitude.
    (i) Frequently carrying out the investigation or experiment systematically.
    (ii) Reporting the exact data or observation from the experiment.

  • C5P3 - Cooperation.
    (i) Always shows cooperation when carrying out group activities.

  • C5P4 - Responsibility.
    (i) Always shows self-confidence while carrying out an investigation and being brave to defend one's ideas.
    (ii) Always ensure the safety of oneself, friends and the surrounding.

Hypertension (High Blood Pressure)

Definition

Hypertension means high blood pressure. This generally means:
· systolic blood pressure is consistently over 140 (systolic is the "top" number of your blood pressure measurement, which represents the pressure generated when the heart beats)
· diastolic blood pressure is consistently over 90 (diastolic is the "bottom" number of your blood pressure measurement, which represents the pressure in the vessels when the heart is at rest)
Either or both of these numbers may be too high.
Pre-hypertension is when your systolic blood pressure is between 120 and 139 or your diastolic blood pressure is between 90 and 99 on multiple readings. If you have pre-hypertension, you are likely to develop high blood pressure at some point. Therefore, your doctor will recommend lifestyle changes to bring your blood pressure down to normal range.

Overview, Causes, & Risk Factors
Blood pressure is determined by the amount of blood pumped by the heart, and the size and condition of the arteries. Many other factors can affect blood pressure, including volume of water in the body; salt content of the body; condition of the kidneys, nervous system, or blood vessels; and levels of various hormones in the body.
· "Essential" hypertension has no identifiable cause. It may have genetic factors and environmental factors, such as salt intake or others. Essential hypertension comprises over 95% of all high blood pressure.
· "Secondary" hypertension is high blood pressure caused by another disorder. This may include:
· adrenal gland tumors
· kidney disorders
· use of medications, drugs, or other chemicals
· oral contraceptives
Hypertension Symptoms & Signs
Usually, no symptoms are present. Occasionally, you may experience a mild headache. If your headache is severe, or if you experience any of the symptoms below, you must be seen by a doctor right away. These may be a sign of dangerously high blood pressure (called malignant hypertension) or a complication from high blood pressure.
· tiredness
· confusion
· vision changes
· angina-like chest pain (crushing chest pain)
· heart failure
· blood in urine
· nosebleed
· irregular heartbeat
· ear noise or buzzing

Hypertension Prevention
Lifestyle changes may help control high blood pressure:
· Lose weight if you are overweight. Excess weight adds to strain on the heart. In some cases, weight loss may be the only treatment needed.
· Exercise to help your heart.
· Adjust your diet as needed. Decrease fat and sodium -- salt, MSG, and baking soda all contain sodium. Increase fruits, vegetables, and fiber.
Follow your health care provider's recommendations to modify, treat, or control possible causes of secondary hypertension.

Hypertension Treatment
The goal of treatment is to reduce blood pressure to a level where there is decreased risk of complications. Treatment may occur at home with close supervision by the health care provider, or may occur in the hospital.

Medications may include diuretics, beta-blockers, calcium channel blockers, angiotensin-convertingenzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or alpha blockers. Medications such as hydralazine, minoxidil, diazoxide, or nitroprusside may be required if the blood pressure is very high.
Have your blood pressure checked at regular intervals (as often as recommended by your doctor.)

Lifestyle changes may reduce high blood pressure, including weight loss, exercise, and dietary adjustments .