FORCE, ENERGY and WORK
Force is needed to pull or push something.
You cannot move an object without using force.
Ex: you cannot push a ball without using force.
To move a light object like pencil, you will have to use less force and to move a heavy object like a table, you have to apply more force.
Force can slow, stop or change the direction of a moving object.
Energy is the ability
to do work.
When you apply force
on an object, your body uses energy
Ex: to move a table, you apply force and to do so your body uses energy.
produces energy from the
A moving car uses energy from the fuel
Whenever force is applied, energy is used.
Work is done only when an object moves over a distance on applying force.
Ex: if you move a pencil, work is done, but even after applying lots of force, if you are not able to move a pencil, no work is done.
We use energy from different sources in our day to day life.
- Food: Your body gets energy from the food you eat.
- Electrical energy: It is used to operate fans, computers, machines, refrigerators and many other things in homes and factories.
- Burning wood, coal and Liquified Petroleum Gas (LPG): It is used to cook food.
- Solar energy: It is used for heating and lighting.
use sunlight to make
- Petrol or Gasolene and Diesel: It is used to run cars, trucks and airplanes.
- Wind energy: It is used to work pumps in agricultural fields.
Machines are used to make certain tasks easy.
Machines like bicycle, sewing machine etc are made up of many parts.
They are called complex machines.
Some machines are very simple.
Like any other machine, a simple machine helps us to perform certain tasks with ease.
Ex: Needle, knife etc.