Electricity

1. The 4 main sources of electricity are dry cell, accumulator, dynamo and solar cells.

 2. All of the bulb in the electrical circuit will light up if the batteries, connecting wires, switches or the bulbs themselves are not faulty.

3. There are 2 types of electrical circuits :

    -series circuits

    -parallel circuit

4. The differents between these 2 circuits can be explained in term of:

    -the arrangement of electrical components in the circuits.

    -the number of paths the electricity takes.

Series circuit :

Parallel Circuit:

 5. Safety precauntions must be taken when handling electrical appliances.

6. Without proper handling of the electrical appliances, one can be exposed to various dangers such as electrical shock, burn, fire and electrocution.

Strength and Stability

1. Many other objects are made up of some of these basic shapes.

2. Things that are stable do not topple or fall down easily.

3. The stability of an object means how stable the object is.

4. If you push the cupboards to the right, cupboard A will topple or fall faster.

 5. One of the factors that makes cupboard B more stable is its shape.The shape of cupboard B gives it a bigger base area.

6. Apart from the base area, the height of an object also affects its stability.

7. For example, if you push both cupboards as shown below to the right, cupboard B will fall or topple first because it's taller.

8. The stability of an object is affected by its base area and height.

9. The factors affecting the strength of structure are the types of materials used and the way a structure is placed.

Absorption

What is the definition of “absorption”?

Absorption can be defined as taking one thing into the area of another. One good example is 'a sponge'. A sponge will absorb or take in water from another area and put it inside of itself.

Which Type of Materials Can Absorb Water?

Some materials can absorb water while some cannot. The materials that can absorb water are called "absorbent materials" and the one that cannot absorb water are called "non-absorbent materials".

Absorbent materials are:

textile products that are made of cloth (cotton, silk, wool) for examples towels, handkerchiefs, t-shirts, undergarments, socks, jeans, denim, robes, traditional cloth diapers, shirts, ties, blouses, formal dresses, lingerie, pyjamas, kimonos, blankets, carpets, woolen garments and etc.

objects that are made of cotton for examples cotton bud, coffee filters, cotton wool, face cotton, floor mop, thread and etc.

objects that are made of wood for examples envelopes, toilet roll, books, tissue paper, newspaper and etc. Coconut-husk and tree trunk also can absorb water.

other objects such as sponges (natural and synthetic) and feathers.

Non-absorbent materials are:

objects that are made of metal for examples key, nail clipper, coin, tin can and etc.

objects that are made of rubber for examples eraser, rubber gloves, tyre and etc.

objects that are made of plastic for examples plastic pail, plastic bag, cutting board, rain coat, umbrella, tent, polystyrene container and etc.

objects that are made of glass

other objects such as pebbles, stones and marbles.

Absorption Ability Are Differ from Materials to Materials

Different materials have a different ability to absorb water. Some materials can absorb more water than others. For example, a sponge can absorb more water than a roll of newspaper.

Experiment on Sponges

The ability to absorb water can also be differ from sponges to sponges and the following circumstances are taking into account.

material - man-made sponges commonly made from cellulose wood fibres or foamed plastic polymers

size - a large sponge can hold more water than a small sponge

condition - a dry sponge can hold more water than a wet sponge because the wet sponge is closer to saturation and as such cannot hold more water. Sponges with more tiny holes can absorb more water than the sponges with less tiny holes

fluid - the type of fluid being absorbed, water or water-based solutions

Simple Machine

We use machines to make our work easier,

and also to help us lift or move objects. 

Sometimes we use simple machines by themselves, 

and sometimes we combine them to create more complex machines.

A simple machine is a machine with few or no moving parts.

There are seven types of simple machines:

-Wedge

-Inclined Plane

-Screw

-Lever

-Wheel and Axle

-Pulley

-Gears

 

Machine	Definition	Examples
Wedge	A wedge consists of two back-to-back inclined planes. A wedge looks like an inclined plane but it works differently. It can either hold things together, as in a doorstop or nail, or it can split things apart, as in an axe or chisel.	Doorstop, Nail, Axe, Chisel, Dart, Knife, Thumbtack,Jackhammer,Zipper,  Screwdriver
Inclined Plane	An inclined plane is a ramp. It helps us to move heavy objects more easily. We use less force but we have to apply the force over a greater distance. Friction is one problem encountered in using a ramp to move heavy objects.	Stairs, Handicap Ramps, Truck Loading Ramps, Bottom of a Bath Tub
Screw	A screw is an inclined plane wound about a cylinder or shaft. The ridges are called the thread of a screw.  The inclined plane allows the screw to move itself or to move an object or material surrounding it when rotating. To remove a screw you have to turn in the opposite direction with a screwdriver. It is very difficult to remove a screw by pulling it straight out.	Screws, Corkscrews Spiral Slides, Spiral Staircase
Lever	The lever is a bar that turns on a point called a fulcrum. Any tool that pries something loose is a lever. Pushing down on one end of a lever results in the upward motion of the opposite end of the fulcrum.	Seesaw, Hockey Stick, Snow Shovel, Wheelbarrow, Baseball Bat, Hammer
Wheel and Axle	A wheel and axle is really two machines in one. In one way it can help roll something along. Wheels cut down on the amount of friction between what you are trying to move and the surface you're pulling it against. A wheel and axle is also like a level in the round. A door knob or a faucet on a sink are really round levels and the "fulcrum" is in the middle where the axle turns.	Bicycles,  Tires, Skateboards, Steering Wheel, Door Knob
Pulley	Pulleys are wheels with grooves around the rim. This groove is for a rope or belt to move around the pulley. Pulling down on the rope can lift an object attached to the rope. Work is made easier because pulling down on the rope is made easier due to gravity.	Cranes, Flag Poles, Sailboats, Mini-blinds
Gears	Gears are one way to transfer motion from one place to another. They work together in groups of two or more. One gear turns another, which may turn another, and so on. Gears are measured by counting the number of teeth they have. When the teeth of two gears fit together and one gear turns, it will cause the other gear to turn, but in the opposite direction. In any pair of gears the larger one will rotate more slowly than the smaller one, but will rotate with greater force.	Clocks, Bicycles, VCR, Grandfather Clocks

Acid and Alkaline / Asid dan Alkali

A. PROPERTIES OF ACIDIC, ALKALINE AND NEUTRAL SUBSTANCES

SIFAT-SIFAT BAHAN BERASID, BERALKALI DAN NEUTRAL

 a. Different foods have different tastes because of their chemical properties.

Makanan mempunyai rasa yang berbeza-beza kerana sifat kimianya.

b. The chemical properties of food are determined by the acids or alkalis in them. 

Sifat kimia ditentukan oleh kandungan asid atau alkali didalamnya.

HOT TIPS:- ASID => MASAM , ALKALI => PAHIT , NEUTRAL => TAWAR, MANIS DAN MASIN.

 ACIDIC SUBSTANCES / BAHAN BERASID

VINEGAR/CUKA

ALKALINE SUBTANCES / BAHAN BERALKALI

TOOTHPASTE/UBAT GIGI

NEUTRAL SUBSTANCES / BAHAN NEUTRAL

SALT/GARAM

Eclipes

Eclipse Geometry and Eclipse Seasons

The geometries for solar and lunar eclipes are:

We see that we can have solar eclipses only during the new moon phase and that lunar eclipses will only occur during the full moon phase. But, wait a minute. New moon and full moon occur every month. We have eclipse seasons that occur roughly every 6 months (during eclipse seasons).

Constellation

What is constellation?

A group of stars that appear to form a pattern in the sky or appear visibly related to each other. Examples are Orion (which appears like a human figure with a belt, often referred to as "The Hunter"), Leo (which contains bright stars that outline the form of a lion),Scorpius (which can seem reminiscent of a scorpion), and Crux (a cross).

Used by the human from long time ago for directions and navigations especially the sailors during their quests across the continent searching for fame and glory. These constellation also used by the farmers to indicate the time of the year specifically the season for planting and harvesting crops.

How to identify them?

There are 88 official constellations defined by the IAU (International Astronomical Union) are mostly based upon those of the ancient Greek tradition but the most common constellation used in human life are The Big Dipper, Southern Cross, Scorpio and The Orion.

1. The Big Dipper

Can be seen in the North Pole between April and June, around 8 pm to 10 pm.

A group of seven bright stars that form a pattern of bowl with a long handle.

To indicate the spring season

The North Star indicates the direction to the north.

Only visible in the northern hemisphere.

2. The Southern Cross

Can be seen in the South Pole between April and June, around 8 pm to 10 pm.

A group of four bright stars that form a pattern of cross with the vertical axis pointing the south.

Can only be seen in the southern hemisphere

To indicate the spring season

3. The Orion

Can be seen between Junes and August, around 8 pm to 10 pm.

It represents the greatest Greek hunter with a belt and sword.

To indicate the winter season.

4. The Scorpio

Can be seen between December and February, around 8 pm to 10 pm.

It represents the scorpion with a head, long body and stinger.

To indicate the summer season.

5. The Aquarius

 Aquarius indicates the autumn season.

Used by farmers to determine the time to begin planting during summer or harvesting crops during autumn.

The Magic of Magnets

Magnets are objects that produce an area of magnetic force called a magnetic field. Magnetic fields by themselves are invisible to the human eye. Iron filings can be used to show magnetic fields created by magnets Magnets only attract certain types of metals, other materials such as glass, plastic and wood aren't attracted. Metals such as iron, nickel and cobalt are attracted to magnets. Most metals however are not attracted to magnets, these include copper, silver, gold, magnesium,platinum, aluminium and more. They may however magnetize a small amount while placed in a magnetic field. Magnetism can attract magnetic objects or push them away. Magnets have a magnetic north pole and a magnetic south pole. If the same pole of two magnets are placed near each other they will push away (repel), while if different poles are placed near each other they will pull together (attract). Magnetic objects must be inside the magnetic field to respond, which is why you may have to move a magnet closer for it to have an effect. The Earth's core is believed to be a mix (alloy) of iron and nickel, giving the Earth its own magnetic field. The Earth's magnetic field is responsible for deflecting the solar wind, charged particles that come from the Sun. Magnetic compasses use the Earth's magnetic field to help navigate in north, south, east and west directions. Electromagnets are created by an electric current running through a surrounding coil.  They have many uses including the generation of electricity in hydroelectric dams. CYLINDRICAL MAGNET U-SHAPED MAGNET BAR MAGNET HORSESHOE MAGNET RING MAGNET

Food Chain and Food Web

FOOD CHAINS FOLLOW A SINGLE PATH AS ANIMALS EAT EACH OTHER.

EXAMPLE:

THE SUN provides food for GRASS

The GRASS is eaten by a GRASSHOPPER

The GRASSHOPPER is eaten by a FROG

The FROG is eaten by a SNAKE

The SNAKE is eaten by a HAWK.

FOOD WEBS SHOW HOW PLANTS & ANIMALS ARE INTERCONNECTED BY DIFFERENT PATHS.

EXAMPLE:

TREES produce ACORNS which act as food for many MICE and INSECTS.

Because there are many MICE, WEASELS and SNAKES have food.

The insects and the acorns also attract BIRDS, SKUNKS, and OPOSSUMS.

With the SKUNKS, OPPOSUMS, WEASELS and MICE around, HAWKS, FOXES, and OWLS can find food.

They are all connected! Like a spiders web, if one part is removed, it can affect the whole web.

FOOD WEBS show how plants and animals are connected in many ways to help them all survive. FOOD CHAINS follow just one path of energy as animals find food.

Alat Pengukuran dan Unit Piawaian

*Pada zaman dahulu,manusia menggunakan proses-proses yang berulang secara seragam untuk mengukur masa.
*Berdasarkan prinsip ini,mereka mencipta alatan mengukur masa.
*Alatan dibawah digunakan oleh manusia pada masa dahulu untuk mengukur masa.

JAM MATAHARI

                                                         
                                                                                JAM AIR

JAM PASIR

JAM LILIN

                                                                             
*Kini,alatan yang dicipta untuk mengukur masa dalam unit piawai
*Unit piawai untuk masa ialah:
a)saat
b)minit
c)jam
*Unit piawai ini membolehkan kita mengukur masa dengan tepat.
*Hubung kait diantara unit-unit itu seperti yang berikut
60 SAAT=1 MINIT
60 MINIT=1 JAM
24 JAM=1 HARI
*Alatan yang ditunjukkan di bawah digunakan pada masa kini untuk mengukur masa

JAM RENDEK

JAM TANGAN BERDIGITAL

JAM DINDING

JAM BERDIGIT