Science: Forces: Friction

Force that acts in opposite direction of a moving object = friction

It can slow down/stop the motion of the moving object.

Friction is (usually) greater when an object moves on a rough surface than on a smooth one. 

Friction between two moving objects produce heat, and causes wear and tear.

Science:Forces:Elastic Spring force

A spring is elastic; goes back to original shape & length after being compressed/stretched. (not over-stretched)

How it works

Force act on spring => spring stretched/compressed => spring exert elastic spring force on object that is compressing/stretching it.

Science:Forces:Gravity

Gravity = force of attraction between two masses.

An object on Earth has weight because of the gravitational force between the object and Earth.


Additional

Mass = amount of matter in an object
Weight = gravitational force that acts on the object.

Science:Forces:Magnetic force

Magnets attract objects that are made of magnetic materials.
Forces exerted by magnets = magnetic forces.
A magnetic force can act at a distance.
Force of attraction = magnetic force of attraction
Force of repulsion = magnetic force of repulsion

Science:Types of Forces

There are four types of forces. They are:
-Frictional force/Friction
-Gravitational force/Gravity
-Magnetic force
-Elastic spring force

Science:Introduction to Forces

This is taken from my textbook. No copyright infringement intended.


Forces:
-is a push/pull
-can make a stationary object move.
-make a moving object move faster.
-change the direction of a moving object.
-slow down a moving object.
-stop a moving object
-change the shape of the object.

English: Past perfect tense

Use of had + past participle = to talk about the action that happened first

Example: After young Mandela had jumped onto the donkey, it unseated him.

Young Mandela jumped onto the donkey first, then the donkey unseated him. For the second action you use simple past tense.

Past perfect tense is formed when past participle of the verb follows had.

Science:Cells

Taken from the PSLE Science Revision Guide, I would simplify the information, I hope you understand what am I posting.

Cell(s):
-smallest unit of life
-able to grow, take in food, reproduce and react to changes in the environment.
-come in different shapes, sizes and structures
-too small to be seen by the naked eye.
-has a nucleus, cytoplasm and cell membrane. (animal cell)
-has a nucleus, cytoplasm, cell membrane,(chloroplast) and cell wall.

Maths: Decrease in percentage

Hello visitors to my blog! I'm posting this because I've posted "Increase in percentage" post, here's the link to view the post:http://revisioning-blog.blogspot.com/2011/03/maths-increase-in-percentage.html

Ok so basically it's the reverse. I'm using the same question in the post, but just change the conditions so the question will be about the decrease in percentage. Please stop the music if you find it annoying, hehe....

So here's the question: The temperature of a piece of metal was 36 degrees. It was then lowered into a glass of cold water and the temperature of the piece of metal decreased to 32 degrees. Find the percentage decrease in temperature of the piece of metal. Round it off to 1 decimal place.


Solution(2Steps):


1st step: Find the difference between 36 and 32.
36-32=4
2nd step: Put 4 over 36 and multiply it by 100%.
4/36 x 100% =(approximately) 11.1%


So here's your answer: 11.1% This post is like introducing short-cuts to Maths questions....

Science: Energy and Photosynthesis(P5 topic)

light + carbon dioxide + water => sugar(food) + oxygen

Chlorophyll trap sunlight.
Most stomata found underside of the leaf.

Extra:Game added!

Hello visitors to my blog, I'm now introducing a game called Penguin Diner, though I've forgotton if it is version 1 or 2-I'm so forgetfull! I hope you like this game, and you could also request for other games, I would try to put it into the blog. Use the C-Box to request for anything you would like to have in this blog. You could also use the C-Box to suggest, comment or to simply have a chat. I hope you like this blog!

Science: Light

I felt that I have to post this, for revisioning purposes. Also, my mother is subjecting me to read books. If I posted this, at least it will give me an excuse to use the computer and get into facebook.....Anyways, the post!

• Light is a form of energy.
• Light = not matter
• Light don't occupy space, it do not have mass.
• Sun = most important source of light.
• Stars give off light.
• Mirrors reflect.

If you have any questions, you can ask by posting at the C-Box. I will try to answer them!

Science: Adaptations for coping with physical factors of the environment

The physical factors of environments:

• Light
• Water
• Temperature
• Air
• Soil

Light is used for
-seeing
-photosynthesis

Seeing in the dark
Cats and owls have large eyes with light sensitive cells, able to see well at night, can hunt for food or escape from danger.

Plants need light for photosynthesis, some plants uses their roots to climb up trees and obtain more light, it enables its leaves to grow bigger.

Aquatic plants need light too. The flowers and leaves of water lilies stay above water.

The leaf stalks of water hyaciths are spongy. They have air spaces for the leaves of water hyaciths to stay above water.

Water
Water = essential for life

Fishes have streamlined bodies. Streamlined bodies = a body that has a pointed head and end, while the middle is bigger and broader.
Streamlined bodies helps a fish to move easily in the water by reducing friction between its body and the water. Its fins help it to balance and move in water.

Aquatic animals have gills to help them breathe underwater. Dophins and whales have blowholes on top of their heads. They can hold their breath for a long time underwater before surfacing to breathe.

Water scopions, water stick insects and mosquito larva have breathing tubes/air tubes which extend out of the water surface to help them breathe in air.

Camels drink a lot of water at a time. Some desert plants have deep and long roots. Others have shallow roots which are spread across a large area to absorb water.

The leaves of cactus are reduced to needles. The thick and fleshy stems store water, also have a waxy surface and few stomata.

Extra: Change in Taemin's picture

This previous Taemin picture was dedicated to my cousin, who was a big fan of Taemin. But she did not like the picture, and wanted me to change it. I changed the picture and she liked it! Yes, for Taemin fans who want the previous picture, you can request for it to be either put in the blog or sent to you in the C-box under Taemin's current picture.

Science: Environment: Introduction

Organism = a living thing

Habitat = Place where an organism can find four things: food, shelter, protection and mate.

Population = a group of many organisms of the same kind, regardless of stage in life.

Community = many populations living together in a habitat.

Environment = factors that affect survival/physical characteristics, they are:

• temperature 
• water
• air
• light
• soil

Science: Introduction of Adaptations

Note: This "Adaptations" post is taken from either my textbook or the PSLE Science Guide, no copyright infringement intended!!!!
Adaptations = characteristics which help an organism survive in (its) habitat.

• Organisms have special characteristics or features that help them to:

          -survive in their habitat
          -reproduce

Structural Adaptations
Organisms have special body parts or unusual life processes which are suited for the environment. They are called structural adaptations.


Behavioural Adaptations
Organisms behave in certain ways to survive in their habitats. These are behavioural adaptations.

Organisms may have both structural and behavioural adaptations to help them survive/reproduce.

Continued in next post!