Issuu on Google+

• YOUR HEALTH: Common Cold, 6 • EARTH TRUSTEE: Collect, Earn and Save!, 7 • HOW DOES ?: A Barometer, 10 • COMPUTER RACY: Getting Wired!, 11 • INTEREST : Tornado in a Jar!, 14

TThe Science Sc ce andd Technology TTe h l gyy Magazine Mag e of Student’s d ’s Digest D ges es Publications P b ti Vol. XIII • No. 6 • January – February 2009 • ISSN 0118-3567

SDMAGS.NET

Precious Fuels CONCEPT MAP: How the Sun Affects Earth • 8-9 CONCEPT ARTICLE: Extreme Weather • 12-13

What are fuels? How important are they in our daily lives? Learn more about fuels and some important issues about them.


Values Corner

S&T

Update

Update

How important? Ω Ezekiel T. Manalaysay

Artworks for studying coastlines Researchers in the United Kingdom will examine artworks from 1770 to 1920 of the coastal scenes of the Isle of Wight, a British island and county from the south coast of England. They believe that this will help them better understand the threats of rising sea levels, coastal soil erosion, flooding and climate change. The artworks can provide a clear picture of what happened to the British coastlines over the centuries.

How important is weather in our daily lives? How can it affect us? Oftentimes, we complaiin that the weather is too ho ot, or too cold or it is raining g hard. We do not recognizee the benefits we get from su uch types of weather. Think about these benefits. Rain gives water to plants and animals. Far mers cannot grow their crops without rain. On a sunny day, sunlight helps green plants make their food. The sun’s heat keeps us warm and dries our clothes. No matter how unpredictable the weather is, we all benefit from it.

SDMAGS.NET

Nila V. M Ni Mata ta, Publbisher • LLillia M. Ra R ba b go o, Ph.D., Scien i ce Educa ducation ti Con Consult sultant ant • Car arme melilita ta C C. Co Coro rone nell & Ce C lilinia J. Dicen, • Antonette Yap– p Caastillo lo,, Supe Supervis rvising ing Edit Editor or • Karla P. Abulencia, Ezekiel T. Manalaysay & Jenilee A. Abene es, Staff Writers • Francisco DC. Mendoza, Art & Design Supervisor • P aull Da D vid id D. D A Arccoss, Graphic/Layout Artist • Noel L. Perez, Area Editors

Imageset Imag esetting ting & Strip Stripping ping Sup Supervi ervisor sor

S&T Diges Digestt Gra Grade de 3 edit edition ion is pub publis lished hed quart quarterl erlyy dduri uring ng the schoo schooll yyear ear by SD Pub Public licati ations ons,, Inc. Inc. with bus b iness and editorial offices at Vibal Publishing House, Inc., G. Araneta Ave. cor. Ma. Clara St., Quezon City • Tels.: 712-2722 loc. 319/ 712-9 2 156 56 to t 59. E-mai mail:l: sdm sdmags agsonl online ine@gm @gmail ail.com com. Mem Member ber:: Phil Philiippiine Educa Educatio tional nal Publi Publishe shers rs Ass Associ ociati ation on • App pproved as a supplementary material for science and technology by the Department of Education (DepEd) per letter dated September 18, 20 mat 2000. 00

2

S&T DIGEST • GRADE 3


What's in a Name? Tropical cyclones are called by different names, depending on their strength and location. Those with maximum winds between 35-64 kph near the center are called tropical depressions. Once their wind speed reaches 65-118 kph, they become tropical storms. Those with wind speeds reaching 119 kph or more are called hurricanes in the North Atlantic and eastern Pacific regions and typhoons in the western Pacific areas.

The spinning Earth How fast does the Earth turn? It depends on where you are standing! At the north and south poles, Earth is hardly spinning. As you go toward the equator, the rate of spin increases. At middle latitudes, the speed of Earth’s spin ranges from 1125 to 1450 kilometers per hour (kph). At the equator, Earth turns at about 1674 kph. Compare this with the speed of an average car which can reach a maximum speed of 240 kph.

SDMAGS.NET A long sleep Hibernation is the state of inactivity that some animals undergo during cold weather. The cold weather, such as winter, prevents them from getting food. Hibernating animals conserve energy by using their “energy reserves” (body fats) at a very slow rate. A hibernating animal appears dead because it does not move at all.

S&T DIGEST • JANUARY – FEBRUARY 2009

3


Precious Fuels SDMAGS.NET Ί

o you often hear your parents complain about the high prices of gasoline, diesel and liquefied petroleum gas (LPG)? These three things are important commodities used by almost every household in the country. They are also examples of fuel. The demand for fuel Fuel is any material that is burned or changed in order to produce energy. The energy obtained can be used to heat an object or to make it

4

S&T DIGEST • GRADE 3

Manuel C. Agbunag II

move. A fuel can store energy and release it only when needed. People can also control the way this energy is released to make it useful to them. Fuel has many uses. People use it to heat and cook food, to run vehicles, to make machines work, and to generate electricity. It is no wonder that there is a huge demand for fuel all over the world, making it one of the most precious commodities on Earth.

Kinds of fuel There are many kinds of fuels but theyy can be g generallyy classified


into two: (1) renewable and (2) nonrenewable. Renewable fuels are those which can be replaced at a rate that is comparable to the rate in which they are used. Examples are biofuels. These are obtained from dead plant or animal materials. They include wood, charcoal, grass cuttings, animal manure, agricultural wastes and biodiesel. Nonrenewable fuels, on the other hand, cannot be replenished as fast as they are consumed. Fossil fuels, such as coal, oil and natural gas, are nonrenewable fuels. They were formed from the remains of plants and animals that died millions of year ago.

environment. Burning fossil fuels emit high levels of carbon dioxide and other pollutants into the air. These pollutants contribute to the formation of acid rain, smog and the worsening global warming. Many governments all over the world are now looking for better alternatives to fossil fuels. As we await for the results of these studies, why not help in their cause by doing simple things that can lessen the use of fossil fuels, such as saving electricity and gasoline?

SDMAGS.NET

Fuel issues At present, fossil fuels are still the most widely used sources of energy in the world. If the high demand continues, their reserves may soon be depleted. As the supply becomes limited, the price will surely increase. After all, it will take millions of years before fossil fuels can be replenished. Another issue related to the use of fossil fuels is their impact on the

acid rain – rain with increased acidity brought about by atmospheric pollutants smog – a thick haze caused by the action of sunlight on air polluted by smoke and vehicle exhaust fumes global warming – the increase in the average temperatture off Earth’ss atmosphere and oceans

S&T DIGEST • JANUARY – FEBRUARY 2009

5


Common Cold Ω

hen you are sneezing a lot, have a runny nose, lot nose a sore throat and a cough, then you have probably caught the common cold. Usually, this disease is the reason why children go to the doctor and have to be absent from school. Children can catch the common cold as often as eight times each year. The common cold affects the nose, throat and ears. It is caused by a virus (a tiny organism that brings illnesses) that is easily passed on from one person to another. There are more than 200 kinds of colds viruses. Other symptoms of the common cold are headache, mild fever, fatigue and loss of appetite. These symptoms may last for one to two weeks.

Myren G. Mana Mannaala layyssay ay

Many people le b believe that going outdoors on a cold weather or o eexposing oneself to the wind can cause tthe common cold. But a person can’t ccatch the common cold through these. The cold virus can spread in the air T tthrough sneezing or coughing. It can also be passed on through the saliva or mucus. When you have a cold, you can take medicines. However, these will not cure the cold but will only help relieve its symptoms. Your body should fight the cold virus on its own. That is why it is important to keep your body healthy and strong. To prevent catching cold, avoid contact with someone who has it. Take lots of foods and drinks that are rich in vitamin C. If you do catch a cold, be sure to get plenty of rest and drink lots of fluids to help you get better. If the symptoms get worse or last for more than two weeks, you must consult a doctor.

SDMAGS.NET

6

S&T DIGEST • GRADE 3


Collect, Earn and Save! Ω

ave you ever heard of the saying “May pera sa basura?” Do you know that you can earn some cash from your trash? This is certainly an easy way for children like you to earn and save some money. All you have to do is collect trash and sell them! First, you have to properly segregate your trash according to their types. This is called waste management. Here is how you can classify some garbage produced in your house: • Paper: old newspapers, used notebooks, cartons • Bottles: glass and plastic bottles and jars • Scrap metals: empty cans • Biodegradable wastes: fruits and vegetable peelings, eggshells, food scraps, dried leaves and flowers, animal wastes • E-wastes: broken cellphones, computers and other appliances

Ezekiel T. Manalaysay M y

• Plastics: grocery bags, broken toys • Hazardous wastes: old paint, insecticide containers, used batteries After you have segregated your garbage, you can sell them to junkshops, to your community’s materials recovery facilities, to recycling centers and/or to waste trade markets usually found in malls. Garbage does not sell at a high price. However, when you do this regularly, you will eventually save a lot of money. Remember, big things always start small! Besides, selling your trash is not just about the money, it is also one way of showing that you care for the environment. By selling your garbage so that it will be recycled and used again, less trash ends up in landfills. This means that you are doing your share in protecting the environment. So, what are you waiting for? Start collecting trash, earn from it and help save the environment!

SDMAGS.NET

S&T DIGEST • JANUARY – FEBRUARY 2009

7


concept map

SUN

provides

light SDMAGS.NET can be converted to

enables

enables

p

heat to generate

plants to make

needed byy to

electricity

food

see


How the sun affects Earth

energy

The sun provides energy, in the form of heat and light to Earth. These are essential to all life-forms on the planet. Without the sun, living things will not survive.

in the form of

heat SDMAGS.NET keeps

people and animals

used to

cook food

causes

evaporation of water or the first part of the

warm

water cycle


Ί

Julieta P. Valenzuela

ir is essential to life on Earth. Without air, most living things will die. Air is a mixture of several gases. It is invisible to the naked eye. Air pressure is the force exerted on a surface by the weight of the air. It decreases as you go higher from the Earth’s surface because air becomes thinner. Cold air is denser. This is why it exerts greater pressure. When air pressure is high, you can often expect cool temperature and clear skies. Warm air, on the other hand, is lighter. Thus, it exerts low pressure. Low air pressure usually brings rain or storm. Since air pressure tells us what kind of weather to expect, meteorologists (scientists who study the weather) have to find a way of measuring it. They do this by using an instrument called a barometer.

There are two main types of barometers: mercury barometers and aneroid barometers. Mercury barometers consist of a glass tube, which is sealed at one end, and has an open mercury-filled reservoir at the other end. When air pressure is high, it pushes the mercury in the reservoir with more force. This makes the mercury go up into the tube. A scale measures the height of the mercury. The higher the mercury is, the higher the air pressure. Meanwhile, aneroid barometers use a small and flexible metal box, called an aneroid cell, which is sensitive to changes in air pressure. The cell expands and contracts as air pressure changes. This causes levers to move and the pointer to display the reading on the face of the barometer.

SDMAGS.NET

10

S&T DIGEST • GRADE 3

The barometer was invented by Italian scientist Evangelista Torricelli in 1643.


Getting Wired! Ω

ave you get “wired” lately? If you use your computer to connect to the Internet, then you are getting “wired”! Nowadays, even young children are already aware of what the Internet can do for them. Aside from helping them do their homework, it has also given them a new way to make friends, play, learn, discover and explore. What are the things that most children like you do when they go “online”? Most of the time, children use the Internet to help them with their homework. They also play online games and make friends. The Internet has indeed become a very powerful tool for learning, having fun and staying connected. Here are some activities that people do when they connect to the Internet:

EEzekie T. Ezekiel T. Manalaysay ays ysayy ys

• e-mailing and sending instant messages (IMs) to friends and family members who live far; • making friends with people of the same age and who have the same interests (e.g., a comic book superhero online fans club); • joining virtual tours of museums, zoos, etc. found in other countries; and • listening to music and catching missed episodes of their favorite TV shows. Getting wired is a modern way to keep children and adults alike stay connected with the world we live in. But remember, it’s okay to get wired as long as you manage your time wisely and make sure that you have your parent’s guidance while you are online.

SDMAGS.NET

S&T DIGEST • JANUARY – FEBRUARY 2009

11


ExtremeWeather Ω

Eze zekiell T. Manaala l yssay ay

haat is weatherr? Weather is defined d as thee con nditio on of th he atmosp phere in a certtain place at a given n time. It occurss because elements in n the atmosphere, such h ass temperatu ure, moisture and d air movem ment, are constantly changing.

• All dayy, the weaath her was hot and th he sun shonee brighttly. When n night came, rain staarted to pour hard. • It was raining when you left home for scchool one morning. When yo ou arriived in school, thee su un sh honee as if it did not rain at all.

Unpredictable weather No one can really say when it is going to rain or when the next storm is coming — not even a meteorologist (a scientist who study the atmosphere and the weather). He/She can only predict what the weather for the day would be like by observing weather patterns and behavior. Just take a look at the instances below: • One moment, it is hot, then suddenly, rain starts to fall.

Changing weather Weather is a natural process happening in the atmosphere. Most of the time, weather brings things, such as rain, heat and wind, that most life-forms on Earth need in their daily activities. However, because of some of man’s activities (e.g., too much use of fossil fuels, deforestation, etc.), weather conditions have changed. This phenomenon is due to global warming.

SDMAGS.NET

12

S

GRADE ADE 2


Glob bal warming is the increase in temperature of Earth’s atmospherre and oceans. Some scientists believe that this can cause extreme weather conditions thaat arre alreadyy happ pening g or have alread dy hap ppeened in different parts of thee world. Here aree som me off them: • Th he San Diego o forest wildfirre of 2007 in the Uniteed Statess wh hereein n almost 1300 0 squ uare-kkilometers of forestt was burned becaause of extreeme su umm mer heat, leaaving 513 000 people homelless;; • Massive amo ounts of ice are melting in th he Arctic regions caausing an inccrease in the water levell of seas and d oceaans and d flo ooding lo ow-lying areas; • More destructive hurrican ness and storms are being formed d such as Hurricane Katrin na and tyypho oons Frank and Milenyo; • Longer periods of drrought in Australia; and • The wettest summer to occur in the United Kingdom (June 2007) because of heavy rainfall, causing floods in different areas.

backk itts condition 100 years ago is a long and gradual proceess. However, you can always start small. Here are some things that you can n do to o contrib bute to the worldwide caampaign ag gainst gllobal warming g: • Plaantt treees and d other plantts. • Do o nott burn n leaves and otther garbagee. • Buryy biodegradablle trash. • Disposed off yo our garbage propeerly. • Reducce, reeusee and reecycle. • Turn off ellectrical app pliiancess when n nott in use. • Ride a biicycle orr ju ust wallk when the plaace you aree going to is nearr. • Use environmeent-friendly products.

SDMAGS.NET

Preventing extreme weather There is really no quick solution that will prevent these extreme weather conditions from occuring and reoccurring. Healing Earth to bring

fossil fuel – a fuel that is formed in the earth from the remains of plants and animals that died millions of years ago, e.g., coal, oil, natural gas Arctic – the region around Earth’s Northh Polle biodegradable – a material that can be broken down into harmless products by the action of living things

S&T DIGEST • JANUARY – FEBRUARY 2009

13


Tornado in a Jar! Ω Ezekiel

T. Manalaysay

tornado ornado is a violent and a powerful rotating column of air that occurs on Earth. Tornadoes whirl around the center of destructive storms at speeds ranging from 64 kilometers per hour (kph) to 480 kph. When seen from afar, a tornado looks like a giant rotating funnel of cloud that stretches downward to Earth’s surface. It can destroy anything that crosses its path! In this activity, you will not experience the wrath of a tornado. Instead, you will create a tornado without even leaving the safety of your classroom.

You will need: a large glass jar with lid; a few drops of yellow food coloring; dishwashing liquid; water; little toy houses; a teaspoon

SDMAGS.NET

14

S&T DIGEST • GRADE 3

You will: 1. Fill the jar with water until it is about 3/4 full. Put a few toy houses in the jar. 2. Add a few drops of food coloring and about a teaspoon of dishwashing liquid in the water. Put the lid on the jar tightly. Shake the jar well or until bubbles show up. 3. Finally, shake the jar in a circular motion. This will twist the water inside the jar. Observe what happens.


DIIRECTIONS: Read each questtions carefully, then blacken the circle beside the letter that corrresponds to the best answer. Check your answers with your teacher afterwards. 1. Which of the following should be done to prevent soil erosion? ❍ a. Practice kaingin ❍ b. Practice reforestation ❍ c. Gather seeds of plants ❍ d. Cut down mature trees 2. Which of these practices causes water pollution? I. Using pesticides. II. Washing clothes in rivers. III. Throwing used oil in rivers. IV. Disposing of garbage properly. ❍ a. II only ❍ c. II and III ❍ b. III only ❍ d. I, II and III

❍ b. It keeps them beautiful. ❍ c. It is good for their color. ❍ d. It allowss them to make food. 6. What is the main source of light on Earth? ❍ a. electricity ❍ c. moon ❍ b. lamps ❍ d. sun 7. The moon gets its light from the _____. ❍ a. sun ❍ c. comets ❍ b. stars ❍ d. meteors 8. Which of the following items can protect you from the harmful effects of too much sunlight? ❍ a. hat ❍ c. sunglasses ❍ b. umbrella ❍ d. all of these

SDMAGS.NET

3. What great bodies of water cover almost 3/4 of Earth’s surface? ❍ a. lakes ❍ c. rivers ❍ b. oceans ❍ d. seas

4. How do you keep your environment clean and free from pollution? I. Plant more trees II. Cover your trash can III. Recycle nonbiodegradable waste IV. Keep a compost pit in your backyard ❍ a. II only ❍ c. I, II and III ❍ b. IIII only ❍ d. I, II, III and IV 5. Why do green plants need sunlight? ❍ a. It keeps them warm.

9. The weather report tells you that it will be rainy the whole day. How will the clouds look like? ❍ a. Like smoke ❍ b. Like feathers ❍ c. Dark and heavy ❍ d. Like the head of a cauliflower 10. How long does it take Earth to make one complete revolution around the sun? ❍ a. one day ❍ c. one month ❍ b. one week ❍ d. one year S&T DIGEST • JANUARY JAN ANUA UARY RY – FEBRUARY F 2009

15


SOS! Ω Ezekiel

T. Manalaysay

A coast guard ship was on a routine patrol near the South China Sea when the captain spotted a stranded fishing vessel. The captain saw a set of flags waving on the vessel’s deck. He asked his crew members to go over the fishing vessel to help. What do you think is the message? Below is the set of flags seen by the captain, decode the message by using the nautical flag alphabet at the bottom.

SDMAGS.NET A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

(The correct answer is in the Teacher’s Edition.)


S&T Grade3#6