Energy is present in our environment and is inherent in all places and everyday activities, such as running, walking, picking up a mobile phone or riding a bicycle. It facilitates transformations within physical beings. Energy is a characteristic that can be transferred, transported and stored. Furthermore, it is subject to conversion from one form to another and can be conserved in terms of quantity, although some of it is invariably lost.
In this article we are going to tell you What is kinetic energy? and we are going to give you some examples so that it is easy to understand.
What is kinetic energy and how is it produced?
Kinetic energy refers to the energy possessed by a body due to its motion. This form of energy depends on both the mass of the body and its speed. It represents the work potential that allows an object to go from a state of rest to a state of motion at a specific speed.
Kinetic energy arises from motion itself and can be determined using the kinetic energy formula: Kinetic energy is equal to half the product of mass (m) and the square of velocity (v). In a simplified form, this is expressed as: Ec = ½ * mv².
For example, a body that remains at complete rest has a coefficient of kinetic energy of 0. When it is set in motion and experiences acceleration, the body's kinetic energy will increase. However, for the body to return to a state of rest, it must absorb an amount of energy equivalent, but in a negative form, to that which it initially received to begin its movement.
Conversion of kinetic energy into electrical energy
The conversion of kinetic energy into electrical energy occurs through a device known as an electric generator. In this context, mechanical energy, specifically kinetic energy, is transformed into electricity. The initial energy source can come from various natural elements, such as water or wind, which generate movement that subsequently allows the generator to produce electricity.
Kinetic energy is used as a medium to produce electricity or heat. An example of the conversion of kinetic energy into electrical energy is found in the dynamo of a bicycle: the rotation of the wheel causes the dynamo to turn, thus activating the bicycle's light. In the field of renewable energy, another example is the electrical energy generated by mechanisms used in wind energy. This process essentially converts kinetic energy into electrical energy through the movement of the blades located in wind turbines.
Kinetic energy according to the field of study
Kinetic energy has characteristics depending on the field of study:
- In the classical mechanics, the kinetic energy of a body is determined by its mass and velocity, which will invariably be significantly less than the speed of light.
- In the field of relativistic mechanics, the phenomena in which the speed of an object (v) approaches the speed of light, represented in physics by the symbol c, are studied. In such cases, the equation for kinetic energy differs from that of classical mechanics, mainly because this energy depends on the relationship between v and c.
- In the field of quantum mechanics, events involving subatomic particles, including electrons, are articulated. This theory exhibits a significant level of complexity, in which physical quantities, such as kinetic energy, are characterized by wave functions that denote probabilities.
Examples of kinetic energy
Let's give some examples of kinetic energy to make it clear what it is:
- When a person puts a scooter in motion, kinetic energy is generated instantaneously as the scooter starts moving. In the case of a glass vase in free fall, gravitational forces exert influence on the vase, resulting in the build-up of kinetic energy as it descends. This energy is eventually released upon impact with the ground or another surface, causing the vase to shatter.
- When a ball is thrownWhen force is applied to a stationary ball, it accelerates, causing it to cover a specific distance that correlates with the magnitude of the applied force. During its movement, the ball generates kinetic energy.
- A stone rolling down a hill generates kinetic energy, which depends on both the mass of the stone and the speed it reaches during its descent. Similarly, the act of walking also produces kinetic energy, with variations influenced by the person's weight and the speed at which the movement occurs. For example, if one were to run instead of walk, the amount of energy generated would increase significantly.
- A roller coaster vehicleIn an amusement park, a roller coaster vehicle has potential energy until the moment it begins its descent, at which point its speed and mass contribute to increasing the kinetic energy. This kinetic energy will be greater when the vehicle is occupied than when it is empty, since the mass will be significantly greater.
- Knocking a person to the ground involves a specific transfer of kinetic energy. When we run towards a friend and jump over him, the kinetic energy accumulated during the run will exceed that of a stationary position. The body will overcome its inertia, causing the friend to fall to the ground. After the impact, both bodies will combine their kinetic energy and will finally stop when they reach the ground.
Differences between kinetic and potential energy
Energy manifests itself in various forms, including thermal, nuclear, electromagnetic, and mechanical, among others. Kinetic energy, as we mentioned earlier, refers to the energy that an object possesses as a result of its motion. In contrast, Potential energy is defined as the energy that an object has due to its positionFor example, an object located at a height has greater potential energy compared to one located at ground level, which reflects the energy it has in reserve.
I hope that with this information you can learn more about kinetic energy and some examples.