Energy, in the simplest terms, is the ability to do work. It is energy that makes you run, jump, move your toys, and even allows the lamp in your room to give light. Behind every motion and change we see around us, there is energy. Just as a car needs fuel to move, we and all other living beings also need energy to live.

^{Windmill Movement (Created with Artificial Intelligence.)}

So, where does this energy come from and where is it stored? Energy has many fascinating types. Now let’s explore together the two most common ones we encounter: kinetic energy and potential energy.

The Energy of Motion: Kinetic Energy

The energy possessed by all moving objects is called kinetic energy. When you are running, when a ball is rolling, when a swing sways in the wind, or when a bicycle speeds downhill, they all have kinetic energy. In other words, if something is moving, that means it has kinetic energy inside!

^{A Bicycle Speeding Downhill Has Plenty of Kinetic Energy. (Created with Artificial Intelligence.)}

The size of kinetic energy depends on two things: how heavy (massive) the object is, and how fast it is. For example, think of a bowling ball and a tennis ball rolling at the same speed. Since the bowling ball is heavier, its kinetic energy is much greater. Similarly, between two cars of the same weight, the one going faster has more kinetic energy.

^{(Created with Artificial Intelligence.)}

Stored Energy: Potential Energy

Potential energy is the energy stored inside an object. This energy arises from the object’s position or condition. For instance, imagine you are holding a ball in your hand. Because you lifted it above the ground, you have given it potential energy. When you let go, this stored energy is released and causes the ball to fall to the ground.

^{When You Pause for a Moment at the Top of the Slide, You Accumulate Potential Energy. (Created with Artificial Intelligence.)}

We can also see potential energy in other places. When you stretch a rubber band or a spring, potential energy accumulates inside it. When you release the spring, this stored potential energy quickly turns into motion energy, that is, kinetic energy. Just like when you are waiting at the top of a slide you have potential energy, and as you start sliding, this energy transforms into kinetic energy!

Time Travel

When humans learned to control fire thousands of years ago, they actually took the first big step in using energy. Fire gave them energy for warming, cooking food, and lighting up the night.