P5- Solar System

Rotation of the Earth

• The Earth rotates on its own axis from West to East. 
• The axis is an imaginary line that passes through the North Pole and the South Pole.
• It takes about 24 hours (one day) for Earth to complete one rotation.
• At any one time, one side of the Earth will be facing the Sun.
• The half side of Earth facing the Sun will experience day.
• The other half side of Earth facing away from the Sun will experience night.
• It takes 24 hours for a place on Earth to come back to the same position.
• The rotation of Earth brings about day and night.

The Atmosphere

• The atmosphere is a layer of air surrounding the Earth.
• The atmosphere is important to us in various ways
  

1. It acts as a blanket that retains some heat from the Sun, thus keeping the temperature on Earth fairly steady.
2. It protects Earth from the harmful ultra-violet rays from the Sun.
3. The oxygen in the atmosphere is used for respiration.
4. The carbon dioxide in the atmosphere is used for photosynthesis.
5. The other gases in the atmosphere are required for many other processes.

Importance of the Sun

• The light energy given out by the Sun enables plants to photosynthesize, thus enabling the survival of all living things because all living things depend directly or indirectly on plants for food.
• The light energy given out by the Sun enables animals to see and respond to changes in their surrounding.
• The heat energy given out by the Sun keeps organisms warm and provides a suitable temperature for various life processes to take place.
• The heat energy given out by the Sun enables the evaporation of water, thus ensuring the continuity of the water cycle to provide a continuous source of water supply to the organisms on Earth.

Position of the Earth from the Sun

• If the Earth were nearer to the Sun, the Earth would receive too much heat energy and the temperature would increase drastically. The oceans would dry up and most living things would die because of the heat.
• If the Earth were further from the Sun, the Earth would receive too little heat from the Sun and the temperature would fall. The oceans would freeze and most living things would not be able to survive the cold weather. 

REMINDER: Please read up on this chapter in your science guide book.

P6 - Algebra

To be handed in on 11 nov 2008

Simplify the following:
1. (a) 5a+3a-6a
(b)3a+4b-a-b
(c)5x+7y+3z-2x-4y+z
(d)12xy-13xz+5yz-4xz
(e)3a-4a+5a-7a+4
(f)5ab-1.5ab+0.75bc+0.25cb

2. (a)3a-5a+4a
(b)12a+5b-7a-14b-9a
(c)2p-5q+7r-4p+2q-3r
(d)7abc-4bca+6cba-cba
(e)a+b+c+2b-c+3c+a
(f) 2ab+3bc+5ac-5ba+2cb+5ab

P5 - Composition

Fear



I stood rooted to the ground. My legs turned wobbly and I could not move even an inch. A cold chill ran through my body, sending beads of cold perspiration down my spine. With quivering lips, I muttered in an edgy voice, “What could that be?” Fear engulfed me. My heart thumped. I could feel it coming out from my mouth. I could no longer contain my cowardice and broke into tears.





Anger



I clenched my fists tightly, piercing each fingernail into my palms. I bit my lips and took a deep breath. It was of no use. The raging fury in me gushed out through my mouth, “Put that down!” I could no longer contain my temper. Anger engulfed me, taking away all composure I had. Nothing could put out the wild fire in my chest.





Joy



My eyes glittered in bliss. I was riding on cloud nine, making my way to the top of the world. I had never felt better. I was overwhelmed with euphoria. It was so much excitement that I could not contain my joy anymore. The smile on my face extended and I was grinning from ear to ear. I boasted in glee, “What else can I ask for?” Tears of joy welled up in my eyes.





Sorrow



I had not expected it. Sadness had taken over every part of me. It felt like a dagger stabbing right into my heart. Deep grief engulfed me. Tears of sorrow welled up in my eyes. I tried to hold back the beads of helplessness, but to no avail. Nothing else could seep into my dark world, except for, “Why?” There were no answers and only questions echoed in my vacuumed mind.











Embarrassment



I flushed. “Does anyone have a paper bag to spare?” I mumbled in complete embarrassment. How I wished that I could hide myself somewhere to save all this humiliation. Even if it were just a paper bag, it would suffice. Beads of cold perspiration gathered at my forehead. I had never felt worse. Little did I expect myself to be caught in such a situation.





Regret/Guilt



All I needed was a second chance to undo the wrong deed. “Look before you leap, child.” My mother’s advice fell on my deaf ears. My heart ached. It felt like I had just stabbed myself with a dagger. I had only myself to blame and no one would bother to nurse the aching heart of a wrongdoer. Tears of guilt and remorse trickled down my sunken cheeks. I truly regretted my foolish act.

P5 Problem Sums(a) – Jan’08

1. There were 1518 boys and girls in a room. When 2/3 of the boys and 1/5 of the girls left the room, there were twice as many girls as boys remained in the room.
(a) How many girls were there at first?
(b) How many boys were there at first?

2. There were some red, blue and green rubber bands in a box. 2/5 of the rubber bands in the box were red. There were 24 more blue than red rubber bands and 40 green rubber bands. How many rubber bands were there altogether?


3. Jason had a sum of money. He spent an equal amount of money each day. After 6 days, he had 3/5 of his money left. 3 days later, he had $360 left. What was the sum of money he had at first?


4. There were 156 men and women at a party. 1/6 of the men and 24 women left the party. There was an equal number of men and women at the party.
(a) How many men were at the party in the beginning?
(b) How many women were at the party in the beginning?


5. Sam, Jeff and Tom have some money. Sam and Jeff have $150 altogether. If Sam receives $30 more from his mother and Tom receives from his mother 2/3 of what Jeff has, they will have an equal amount of money.
(a) How much money does Sam have at first?
(b) How much money does Tom have at first?

HAPPY NEW YEAR!

Dear all,

Happy New Year to you! May all of us strive for greater heights in the year 2008. Way to go!

Cheers,
Miss Wong

P6 Science

1. What is the energy conversion when an apple drops from an apple tree?
2. What are the factors to consider when choosing which material to use to make an item?
3. What is a force?
4. (a) Name a difference between friction and magnetism.
(b) Why is friction important? List as many points as possible.
(c) Why does friction sometimes become a problem?
5. Alex has 2 objects. How can he prove if they are both magnets?
6. Explain the energy conversion that takes place in a power station.
7. When a ball is dropped from a distance above ground, it bounces but not back to the original height where it was dropped.Why?

P6 Problem Sums Jan'08

Sorry for the delay.

1. Ben bought 3 times as many toy cars as game cartridges. He spent $1615 altogether. A game cartridge costs $15 more than the total cost of game cartridges. Find the cost of a game cartridge.

2. Mrs Lin bought 12 pears and 4 apples. Mrs Wang bought 12 apples and 4 pears. Mrs Wang paid $1.60 less than Mrs Lin. If an apple costs 35 cents, how much did a pear cost?

3. Limei went to the market with $48. This amount of money was just enough to buy 4kg of beef and 3 kg of mutton. Limei, however, bought 3kg of beef and 4 kg of mutton and had $1.50 left. Find the cost of 1kg of mutton.

4. Mr Fu paid $404 for some jackets and T-shirts. A jacket cost $20 and a T-shirt was $8 cheaper than the jacket. If he bought 7 more T-shirts than jackets, how many jackets and how many T-shirts did he buy?

5. On tree-planting day, 40 pupils planted some trees. Each boy planted 3 trees and each girl planted 2 trees. The boys planted 30 more trees than the girls. How many boys were there?

6. Box A contains 50-cent coins and Box B contains 20-cent coins. There are 19 more coins in Box B than in Box A. But the amount of money in Box A is $1.30 more than the amount of money in Box B. How much money was there in Box A?

7. A big tank had 890 litres of water. A small tank had 170 litres of water. When an equal amount of money was added to both tanks, the big tank had 3 times as much water as the small tank. How much water was added to each tank?

8. Ann, Ben and Mike spent $566. Ann spent $176 more than Ben and Mike spent $60 less than Ben. How much Ben spend?

9. Jane is thinking of a number. When it is divided by 6, the quotient is a whole number. When it is divided by 9, the quotient is also a whole number. What is the number?

10. Susan wants to arrange her stamps in columns on a card. If she puts 8 stamps in each column, she will have 2 stamps left. If she puts 9 stamps in each column, she will be short of 4 stamps. How many stamps does she have?

11. A teacher bought 100 cookies for her pupils. If she gave each pupil 3 cookies, she would need 8 more cookies. How many pupils were there in her class?

12.Mrs Lin bought a certain number of rambutans for 5 scouts to be shared equally among them. As one of them had a stomachache, each of the remaining 4 could have an additional 3 rambutans. How many rambutans did she buy for the 5 scouts?