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. Your body produces energy from the food you eat. A moving car uses energy from the fuel it burns. 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.

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.