Page 245 - New Medley 4 Semester 2 PDF (Merged)

years ago. We have very limited amount of these fuels which will get finished

in the near future.

Fossil fuels are called non-renewable sources of energy. In order to enjoy a
comfortable life in future, we must use these resources very carefully, without

wasting them. We should learn to conserve these energy resources.

Nowadays, we are using fossil fuels faster than they are formed. If they get
finished, we would experience an energy crisis. Therefore, in order to avoid this

situation, we should use other forms of energy which we get from the sun, wind
and water. Since these sources cannot be finished, they are called renewable

sources of energy. Renewable sources of energy are non-polluting and do not
harm the environment.

SIMPLE MACHINES

Take two small pieces of cloth. Try to tear one piece
into smaller pieces with your hands. Do you find it

easy? Take the other piece and cut it into smaller
pieces with the help of a pair of scissors. Do you

find it easier now?

When we find it difficult to do work with our hands,
we use some tools. These help us do the work easily.

These tools are called simple machines.

The pair of scissors you used is a simple machine. The simple machines are tools
that make our work easier and faster. This is because they change the direction

of the force applied.

Pliers

Scissors
Bottle
opener

Screw Screwdriver
Nutcracker
Pulley
Some simple machines

243