Energy is the capacity to do work. According to the law of conservation of energy, energy can neither be created nor destroyed. It can only be transformed from one form into another. This means that the loss in one form of energy leads to the rise in the other form of energy. In other words, it represents the idea of a closed system where the energy neither gets produced nor dies out. There are a number of daily life activities in which we can easily observe the application of the law of conservation of energy such as eating food, rubbing hands, burning fuel, etc.
Examples of Law of Conservation of Energy
1. Light Bulb
When the switch connected to the light bulb is pushed or is turned on, the electrical connection between the supply unit and the bulb gets established. The current begins to flow in the closed electrical circuit causing the bulb to glow. Here, the electrical energy gets converted into light energy after entering the internal circuitry of the light bulb. Hence, the light bulb is a prominent example of the law of conservation of energy.
A moving object induces motion into a stationary object after hitting it. This is because the kinetic energy possessed by the moving object can not end abruptly. As per the law of conservation of energy, the energy can only be transferred and cannot be created or destroyed; therefore, the impact force transfers kinetic energy to the stationary object, thereby causing it to move.
3. Object Falling from Height
An object that is placed at a certain height possesses potential energy. When this object is made to fall from the height towards the ground due to the action of the earth’s gravitational pull, the potential energy gets converted into kinetic energy. The transformation of energy from one form to another displays the law of conservation of energy in real life.
4. Burning Woods
The wood or other fuel sources possess potential energy in them. On the burning of these fuel sources, the conversion of potential energy into heat and light energy takes place. The energy does not get consumed during the process. Also, it does not get created; therefore, the implication of the law of conservation of energy can be easily seen.
5. Beating Drum
Have you ever wondered about the science behind the sound produced by beating the drum? The drummer strikes the diaphragm of the drum with sticks and supplies mechanical energy to it. The mechanical energy; therefore, gets converted into another form of energy known as sound energy. Hence, the law of conservation of energy modulates one form of energy into the other and produces sound.
6. Power Plants
The electricity or electrical energy used for commercial and household use is generated by various power generation methods, for example, hydropower plants, thermal power plants, nuclear power plants, etc. Almost all power plants make use of the law of conservation of energy to produce electrical energy. For instance, hydropower plants convert the potential energy of water into electrical energy. Similarly, nuclear power plants convert chemical energy into electrical energy, and so on.
A battery is a combination of cells. The cells are made up of chemical substances and act as a dc power source. The energy generated by a battery is a result of the conservation of energy. The chemical substances contained within the cell undergo a series of reactions and produce chemical energy. This chemical energy is then transformed into electrical energy. The electrical energy produced by the cell can be further transformed into other forms of energy depending on the type of application where the battery is being used, thereby keeping the law of conservation of energy consistent.
Speakers or loudspeakers are the devices that are used to amplify and enhance the sound signal to produce a loud and better version of the input sound signal. The internal circuitry of the speakers converts sound energy into electrical energy. The transformation of energy from one form into the other clearly demonstrates the law of conservation of energy in everyday life.
9. Chewing Food
When we chew and swallow our food, it breaks down into smaller particles and reaches the stomach. This process of chewing and swallowing food requires mechanical energy. After reaching the stomach, the food breaks down and undergoes a chain of reactions, thereby converting the mechanical energy into chemical energy. The chemical energy can further be converted into other forms of energy and can be utilized to perform various daily life tasks such as playing, running, etc.
10. Rubbing Hands
We often feel warm after rubbing our hands together. Let us find out how it works. The process starts when the mechanical energy supplied by our muscles helps us to move our hands back and forth against each other. The motion of the hands is opposed by the force of friction. The mechanical energy; therefore, gets dissipated or converted in the form of heat energy, thereby making us feel warm.
11. Newton’s Cradle
Newton’s cradle is the best product to demonstrate the law of conservation of energy. It consists of a few pendulum bobs attached to a rod with the help of strings. When one bob is pulled to one side and is released, it hits the neighbouring bob; therefore, the energy gets transferred from one bob to the other. This transfer of energy goes on and on till the last bob. The last pendulum bob does not have a neighbouring bob to transfer energy, hence it dissipates the energy by covering the same distance as covered by the first bob. The same experiment can be repeated by pulling two pendulum bobs together, which would displace the last two bobs from their original position. Similarly, for the displacement of the ‘n’ number of bobs from their places, ‘n’ bobs move to the opposite side, thereby displaying the law of conservation of energy