下次再来哟!!

Thursday 22 November 2012

SPRING

Spring (Year 3)

What is a Spring?
A spring is a device or an elastic object or a coiled piece of steel /other materials. A coiled spring also known as a helical spring. 

Source: Wikipedia
A coiled spring changes shapes when applied external force on it and return to its original shapes when force removed. If too much force applied, the coiled spring will permanently deform and will never return to its original shape.

Will a Spring Changes in Size & Shape?
Yes. A spring will change it size and shape when we: 
  • bend it - when a spring is bent, the size and shape of the spring are changed and when let go, the spring returns to its original size and shape;
  • twist it - when a spring is twisted, the size and shape of the spring are changed and when let go, it returns to its original size and shape;
  • squeeze/compress it - when a spring is squeezed/compressed, it becomes shorter and when the spring is released, the spring will return to its original length; 
  • stretch it - when a spring is stretched, it becomes longer and after being released, it returns to original length.

Photo by YEE

What Affect the Stretching Ability of a Spring?
The length or diameter or thickness of a spring affect its ability to stretch more (easy to stretch) or less (difficult to stretch).
  • Length. A longer spring is easier to stretch than a shorter spring. In other words, the shorter the spring, the less it stretches.
  • Diameter. A bigger diameter spring is easier to stretch than a smaller diameter spring. In other words, the smaller the diameter of the spring, the less it stretches.
  • Thickness. A thinner spring is easier to stretch than a thicker spring. In other words, the thicker the spring, the less it stretches.
Different weights of an object that hung at the end of a same spring will give different answer to its stretching ability. The heavier the object hung, the longer the spring stretches.
Mind Map on Spring (Year 3)
Basic Types of Springs
There are 3 basic types of springs.

Extension / Tension Spring
The coils normally touch together and when force applied to stretch the spring, the coils will separate. Examples of objects with the uses of extension/tension springs:
Source: Pohl Spring Works


  • baby hammock - to provide gently bouncing when baby was placed into it
  • stapler - to push the staplers forward and to keep the staplers in place;
  • spring balance - to measure weigh or force

Compression Spring
There are space between successive coils and when force applied to shorten the spring, the coils will push closer together. Examples of objects with the uses of compression springs:
Source: Pohl Spring Works
  • ballpoints pens - to push the nib in and out
  • pogo sticks - to bounce in a standing position off the ground
  • umbrellas - to extend or open it
  • toasters - to spring out the toast automatically when time out
  • mechanical pencils - to push the lead out
  • torches (battery holder) - to allow and hold the inserted battery
  • rocking horse - to allow it to move up and down

No comments:

Post a Comment