What is energy?

Energy helps us to do things. It gives us light. It warms our bodies and heats our homes. It bakes a cake and keeps our milk cold. It runs our TVs and our cars. It makes us grow and move and think. ENERGY IS THE ABILITY TO DO WORK. 

Energy gives us light. Light is a type of energy we use all the time. We use it so that we can see when it is dark. We get most of our light from the sun. That’s why we stay awake during the day. It saves money. Sunlight is free. At night, we must make our own light. Usually, we use electricity to make light. Flashlights use electricity too. This electricity comes from batteries.  

Energy makes things grow. All living things need energy to grow. Plants use light from the sun to grow. They store the energy from the sun in their roots and leaves. Animals can’t store light energy like plants. Animals, including people, eat plants, and use the energy stored in the plants to grow. They store the energy from plants in their muscles. 

Energy gives us heat. We use energy to make heat. The food we eat keeps our bodies warm. Sometimes, when we run or work really hard, we get hot. In the winter, our jackets and blankets hold in our body heat. We use the energy stored in plants and other things to make heat. We burn wood and natural gas to cook food and warm our houses. Factories burn fuel to make the products they sell. Some types of power plants burn coal to make electricity. 

Energy makes things move. It takes energy to make things move. Cars run on the energy stored in gasoline. Many toys run on the energy stored in batteries. Sailboats are pushed by the energy in the wind. After a long day, do you ever feel too tired to move? You’ve run out of energy! You need to eat some food to refuel. 

Energy runs machines. It takes energy to run our TVs, computers and video games-energy in the form of electricity. We use electricity many times every day. It gives us light and heat, it makes things move, and it runs our toys and microwaves. Try to imagine what your life would be like without electricity. We make electricity by burning coal, oil, gas, and even trash. We make it from the energy that holds atoms together. We make it with energy from the sun, the wind, and falling water. Sometimes, we use heat from inside the earth to make electricity. 

Energy doesn’t disappear. There is the same amount of today as there was when the world began. When we use energy, we do not use it up. We change it into another type of energy. When we burn wood, we change its energy into heat. When we drive a car, we change the energy in gasoline into heat and motion. There will always be the same amount of energy in the world. But more and more of it will be changed into heat. Most of that heat will go into the air. It will still be there, but it will be hard to use.