Prevent... from

Eg. The barrier was put up to prevent people from falling over.

You can prevent the sun from shinning into the house by pulling down the curtain.

Amiable Vs Amicable

Amiable – pleasant and easy to get along

Amicable – People show friendliness towards one another and do not want to quarrel

Eg. Susan is amiable and everyone likes her.

Tricia is amicable and does not want to quarrel with the unreasonable boy.

Force

Force = Mass x Acceleration (F=ma)

Work is done only when an object is being moved.

To moved things, we can pull or push (apply force).

Forces can be seen but their effects can be seen and felt.

A force can be seen when:

v A stationary objects moves

v A moving object moves faster

v A moving object changes direction

v A moving objects stops

v The object changes its shape.

Balanced forces do not cause a change in motion.

Gravitational Force

v Is the pull of gravity

v Measured by weight

v Decrease with increasing distance from the centre of the Earth.

v The higher the object is from the ground the more gravitational potential energy.

v The larger the mass, the greater the gravitational force.

v Acts from a distance.

Frictional Force

v Produced when two things rub each other.

v Acts in the opposite direction

v The rougher the surface, the more friction it has.

v The heavier the mass, the greater the friction.

v Advantages: Prevent us from falling.

v Disadvantages: Cause wear and tear and heat – waste energy.

v Use lubricants, rollers and ball bearings to reduce friction.

Elastic Spring Force

v When an object is acted upon by a force, it can be compressed, stretched or bend.

v If the object returns to its original shape after the force is removed, it is said to be elastic.

v Found in rubber band and spring.

Take note of the graph that comes with the question.

The graph above measures the extension – so it starts from 0cm. It did not mention the length of the original spring.

The graph below measure the length of the entire spring – so it does not start from 0cm.

The heavier the mass, the longer the extension. The extension will be constant until it comes to a point where the spring cannot return to its original length.

Magnetic Force

• Magnetism is the attractive or repulsive force that acts between magnetic materials
• Can pass through non-magnetic substances
• Can act from a distance

Consist of = comprise

The ingredients of the soup consist of mushroom, cream and water.

The ingredients of the soup comprise mushroom, cream and water.

Alphabet Vs Letters

A-Z are letters of the English Alphabet.

The whole set of A-Z letters makes up the alphabet.

Cynical Vs Skeptical

Cynical person – assumes and expects the worst of others.

Eg. The cynical manager thinks that we will not be able to anything without him.

Skeptical person – hard to convince

Eg. My mother was skeptical when I told her that I was the first in class.

Prepositions

Prepositions are words that link the person or thing with the rest of the sentences. They also express time, show position or indicate direction.

Examples:

I am going to the zoo today.

There’s a butterfly on my back. Can you get it off me?

I am born in Singapore.

The ruler is made of wood.

Humpty Dumpty has fallen off the wall.

My puppy was missing since 2 weeks ago.

I waited until my parents got home before I go to bed.

We have to think out of the box.

Photosynthesis and Respiration

Only green plants can make food through the process of photosynthesis.

Photosynthesis the process whereby plants make food using water and carbon dioxide in the presence of sunlight in order to produce sugar and oxygen.

Chlorophyll in the plants interacts with sunlight to split the water present into hydrogen and oxygen.

Air is exchange through the stomata which are found mostly on the underside of the leaves.

During photosynthesis, light energy is converted into chemical energy.

Food can be stored in different plant parts:

v Roots – carrots, sweet potato

v Stems – sugarcane, potato

v Leaves – cabbage, onion

v Fruits

v Seeds – groundnuts, maize, rice

A food chain shows how energy is transferred from one type of organism to another.

As energy moves up the food chain, it gets lesser because it has been transformed into other forms of energy.

Green plants and certain types of bacterial and algae are primary producer because they produce usable energy for other living organisms.

Predators and scavengers are known as secondary consumers.

Decomposers are organisms that feed on dead plants or animals and break them down into simpler substances.

Eg. Bacteria and fungi.

Maggots, dung beetles, ants and earthworms are the helpers.

Respiration takes place in all living things – it is the process where energy is released from glucose to carry out life processes.

Breathing is the mechanical procedure in which air reaches the lungs.

Between… and

The word ‘between’ is used with ‘and’.

Eg. I am sitting between John and Sally.

The temperature is between 24 and 32 degree Celsius.

Come to my house between 1pm and 3pm.

Energy (1)

Energy is the ability to do work.

Plants convert light energy from the Sun, carbon dioxide and water into food (sugar).

All energy available on Earth comes from the Sun through the process of photosynthesis.

Solar, wind, wave energy, biomass and geothermal energy and hydropower are examples of renewable energy.

Solar cells can collect energy from the Sun to power satellites and calculators.

Solar energy can be transformed into electricity using the photovoltaic (PV) panels.

Disadvantages of using electricity that is generated by solar energy:

v The Sun’s rays are too scattered and irregular.

v It can be interrupted by the cloud cover.

v The cost of setting up the PV panel may be high.

Energy is constantly changing from one form to another.