What is energy?
Energy is the ability to do work or cause change.
It makes things move, heat up, light up, or grow.
Without energy, nothing would happen—no motion, no light, no life.
Types of Energy
Kinetic energy – energy of moving things (like a running person or a rolling ball).
Potential energy – stored energy (like water behind a dam or a stretched rubber band).
Thermal energy – heat.
Light energy – from the sun or a bulb.
Sound energy – from vibrating objects.
Chemical energy – stored in food, batteries, or fuel.
Energy is never created or destroyed, only changed from one form to another. This is called the law of conservation of energy.
Where is it found?
In Nature:
Sun – gives us light and heat energy (solar energy).
Wind – has kinetic energy.
Waterfalls and rivers – flowing water has kinetic and potential energy.
Inside the Earth – geothermal energy (heat from inside Earth).
Living things – food gives us chemical energy.
In Everyday Life:
Batteries – store chemical energy.
Fuel (like petrol or gas) – stores chemical energy that becomes heat and motion in engines.
Electricity – energy used to power homes, phones, fans, lights, etc.
Moving vehicles – cars, bikes, and trains have kinetic energy.
Why Energy Is Important:
• Keeps Living Things Alive:
All living things need energy to survive. Humans, animals, and plants use energy to grow, move, repair themselves, and stay alive. We get this energy from food and the sun.
• Powers Machines and Technology:
Every machine—like fans, lights, cars, computers, and phones—needs energy to work. Without energy, nothing would function.
• Drives Natural Processes:
The energy from the sun powers the water cycle, weather, plant growth (photosynthesis), and keeps the Earth warm enough for life.
• Enables Work and Activity:
Energy is what lets us lift, move, build, play, and think. It is needed for every type of physical or mental effort.
• Supports Modern Life:
From lighting our homes to transporting people and goods, energy is essential for our daily lives, comfort, and progress.
