Pulley System - Clothes Hanger

This clothes hanger is made of a pulley system that consists of a fixed pulley seen at the top - attached to the ceiling and a movable pulley seen at the bottom that determines the height at which the clothes are hung.

Next

The fixed pulley is necessary as the person (standing below) exerts an effort (pulling string) that makes the load (clothes) go in the opposite direction.

Next

The movable pulley reduces effort used but the trade-off for less effort is that the effort must travel a longer distance than the load. - meaning you will have to pull the string for a longer distance than the distance that the clothes will move up.

Next

If you have one at home, try it out.

Outstanding Stories - SA1 2008

By Tan Guan Jie '

Angry (1) honks could be heard from the ever busy Bukit Timah Road on this cold, rainy Monday morning. I stared out of my father's black Nissan car with a sulky face (3) and at the same time, I tried to ignore father's grumbles about the slow, red lorry that seemed to be holding up the traffic. It was raining cats and dogs, which made driving difficult. And worse of all, I was late for school.

next

I stared at the trees which were lined up along the road. The trees which stood tall and magnificent now looked eerie as lightning crackled (4) and lit up the whole sky. Looking at my watch, I grimaced as I saw that the time was now 7.05am. Soon, my father lost his temper and started beeping at the slow lorry like a mad man (2). And with that, all the cars joined in the beeping. Suddenly as if heaven above was angry, a bolt of golden lightning shot through the sky, hitting a tree squarely onto its foundation. As if the giant tree was responding to the pain, it swayed from left to right as it drew its last breath.

next

The giant tree crashed down onto the frail red lorry. As it smashed onto the metal frame of the vehicle, it disfigured the lorry. Glass shattered and metal was bent! But the worst thing that could happen was the smell of petrol that hung in the air.

next

My father and I did not know what to do. We just sat in the car helplesly while others, with their instincts kicking in, rushed to the scene. Some pried the door opened with giant umbrellas. Others with handphones called the Singapore Civil Defence Force. The thing that caught my attention was a scream that came from the bloodied school girl who was being pulled out of the lorry.

next

Upon seeeing this, a wave of guilt overcame me. If only I had been more patient. If only father had not honked at the lorry. If only... if only.... It was too late to change anything now.

next

Tears started to well up in my eyes as I saw paramedics separate the father and daughter in two flashing ambulances and drive off. But from this, I learnt a valuable lesson - always be patient, a human life is more important.

nxt
Please note:
(1) red: adjectives that tell me more
(2)green: comparisons make effective visuals
(3)pink: feelings - heaven, the tree and the others also have feelings
(4)purple: verbs that create strong visuals and are action packed

Outstanding Stories - SA1 2008

By Wesley Au

Wood-Row Street - an incredible sight.

The street was named after the long rows of stout (1) trees that lined the edges of the footpath. It was truly a sight that resembled peace and tranquility (3) but it almost became a scene of a tragic loss of human life...

next

Wood-Row Street - 2nd January 2006

next

As always, the evening period was the most crowded as many people were returning home from work. I was driving back from work, eyes lazily snapping (4) close from exhaustion. Ahead of me was a husband and wife driving a slow-moving van which was as 'fast' as a lawn-mover (2) ! Sore, irritable and hungry , I angrily punched my steering wheel. But my displeasure quickly turned into sheer terror.

next

A large oak tree directly beside the van emitted a queer, creaking sound and started tilting. "Something is wrong. A thousand-pound tree does NOT tilt!!" I thought wildly as the creaking became more and more pronounced. Shards of bark snapped free from the trunk with a crackle of joy. Then out of the blue, the tree dropped and crashed onto the van!

next

It was horiffic. The hood of the van bent and buckled under the pressure of the seemingly iron-clad tree. I dashed out of my car and instantly sprinted to the van. Several passers-by helped the couple out of the van. Just as a man could not lift an elephant, the van could not take it anymore and got crushed like a lump of tin foil.

next

As I was about to return to my car, the van erupted in a ball of billowing flames. The warmth of the flames greedily feasting on the tree was quickly chased away by the cold rain. "Like a funeral pyre," I thought grimly as I returned to my car. Luckily, someone had called the fire brigade which then proceeded to quench every last glowing ember.

next

Life is unpredictable. Life can as easily reward you as it can curse you! Yet life has a flavour that only someone who has nearly lost it can experience.

next

Please note:

(1) red: adjectives that tell me more

(2) green: similes make effective visuals by comparing one thing to another

(3) pink: feelings - here even the tree has feelings

(4) purple: verbs that create strong visuals and are action packed

Science Lesson 2

Please choose one of the questions below and post your thoughts.

(1) In SAM recently, Wei Zhi wrote about energy conversions and posed the following question:

As we use fossil fuels - natural gas and oil in Singapore to convert chemical potential energy into electrical energy, what are we going to do as these natural resources are running out?

(2) Most of you talked about the chemical potential energy we store from food. You also talked about how we convert this stored energy into kinetic energy through moving aound.
Imagine you are all running around playing football (yes girls included).
Can you think of how we could make better use of this converted kinetic energy while we are running around?

Remember that answers are to make use of your knowledge of concept of conversions of energy.

Label title:
(1) Alternative Source of Electrical Energy or
(2) Alternative Use of Kinetic Energy

Write author's name as usual