Thursday, June 4, 2009

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.

Wednesday, June 3, 2009

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.

Tuesday, June 2, 2009

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.