Understanding Energy Conservation Law | Basics & Examples

What is the Law of conservation of energy?

The law of conservation of energy is a basic law of science, we see everywhere in our daily lives. It tells us how energy works in the world. But don’t worry—it's easy to understand. Let’s dive into what it means; who discovered it and some fun examples will help you understand this.
 

What is the Law of Conservation of Energy?

According to this law, energy cannot be created or destroyed. Only converted from one form of energy to another form of energy. In simple words, total energy of system remains same until energy is added or removed from any external source.

Examples:

A light bulb converts the electrical energy into light and heat energy so you can see in the dark. Another example is burning of wood, burning wood reduce to ashes however burning wood converts chemical energy into heat and light energy.

Beating a drum, converts mechanical energy into sound energy. Just look around and you will find more such examples. If you eat food, your body takes that energy and uses it to move, think or even play games.

Who Discovered the Law of Conservation of Energy?

The law of conservation of energy is a easiest law in science. It says that energy can’t be created or destroyed; it just changes form.

Key Discoverers:

Julius Robert Mayer

• Julius Robert Maier was a German doctor who first thought of this idea in 1842.
• He notices that energy change from one form to another form like heat into movement.

James Prescott Joule

• One more scientist, James Prescott Joule experiments to prove that energy remains same even after its form changed.
• He helped prove this idea with his research.

Main points of law of conservation of energy

Let’s break down the main ideas into simple points:

• Energy can’t be made or destroyed: Total energy of a system remains same.
• Energy can change forms: For example: Light or heat, they both are functions of electricity.
• Energy moves from one place to another: Energy can move through air, water and objects.

What are the derivations of the Law of conservation of energy (Class 9?)

According to conservation of energy law, energy cannot be created or destroyed.  It can only change into different types. Let’s learn how this rule works, especially for students in class 9.

Simple Explanation of Energy Forms

• Potential Energy: This is the energy something has when it’s up high. For example, if you hold the ball up in the air has potential energy.
• Kinetic Energy: This is the energy when something is moving. When your ball starts falling down then potential energy convert into kinetic energy (energy of movement).

Derivation Step by Step

At the Start:

• Whenever a ball is lifted up in the air, potential energy is generated inside us.
• In this case, there is no kinetic energy because the ball is not moving.

When the Ball Falls:

• As the ball falls, the potential energy decreases.
• As the speed of the ball increases, the kinetic energy also increases.

At the Bottom:

• Just before hitting the ground, the kinetic energy of ball is increased and the potential energy of ball is decreased.

At the start, the total energy (potential + kinetic) is equal to the total energy at the end. So, energy is conserved—it just changes from potential to kinetic energy.
 

How Can We Prove the Law of Conservation of Energy?

Even the experiments of scientists can prove this law. Here’s a simple way to think about it:

• Drop a Ball: If you hold the ball up, it stores energy (Potential energy).
• Let It Go: When ball drops, potential energy convert into kinetic energy (energy of movement).
• After It Hits the Ground: It converts the energy into sound as well as heat.

In each step, the total energy remains the same. It only moves or changes form. This show that energy is always conserved.

Law of conservation of energy formula

The formula for the law of conservation of energy is:

Total Energy (Before) = Total Energy (After)

In simple words, total energy of system at the start remains same at the end until energy is added or removed from any external source.

How It Works

• Before: Energy may be potential energy, kinetic energy, stored energy, heat energy or energy in motion.
• After: Energy can be change from one form to another, but the total energy always constant.

When you hold the ball up in the air it stores energy called potential energy. Once you drop it that stored energy converts into movement or kinetic energy. When the ball hits the ground, most of the energy is converted into sound and heat, but the total energy always remains constant.

This formula tells us that energy cannot be destroyed, it change into different type of energy.

Conclusion

The law of conservation of energy is a popular rule in science. It says that energy can’t be made or lost, only changed from one form to another. No matter it is light energy, heat energy or kinetic energy, energy is always conserved.

Remember, energy moves and changes. When you hold the ball up in the air it stores energy called potential energy. Once you drop it that stored energy converts into movement or kinetic energy. When the ball hits the ground, most of the energy is converted into sound and heat, but the total energy always remains constant.

This Law helps us understand how things work around us and why energy is always around us in different ways.

Scientists like Julius Robert Mayer and James Prescott Joule helped us understand this law through their work and experiments. These laws clear to us through more experiments from scientist such as Julius Robert Mayer and James Prescott Joule.