Electrical Energy and Kinetic energy:

The Power can be defined as the ability to work in an electrical current. Like all energy, electrical energy is the property of an electrical system that allows the execution of work. It is achieved through various ways. What we call "electricity" can be understood as Electricity is the phenomenon described electricity does work through electrical charges.

The Power can be a byproduct of other forms of energy such as mechanical and chemical. Through turbines and generators can transform these forms of energy into electricity.

Dynamo is an example of generating electricity, a device that converts mechanical energy into electrical energy. We now know that the variation of the magnetic field generates electrical current. In the dynamo the magnet rotates with the coil around it. This movement generates a changing magnetic field of the magnet, appearing then, an electric current in the set of turns of the coil. This electrical current can be used to light the lamp of the bicycle, for example, or any equipment been installed in the electrical circuit of your car.

The Power can also be processed through equipment in other forms of energy such as thermal energy by Joule effect. What is defined as the phenomenon where a driver is driven by electric current transforming electrical energy into thermal (heat). Phenomenon studied by James Prescott Joule (1818-1889).

The Electricity can be generated by renewable sources such as the powerful waters, the winds. Fonts that are a byproduct of solar energy, because the winds are formed by convection currents and the potential energy accumulated in the falls of water also comes from the sun

One way to generate Electricity occurs in plants, where the potential energy of water is used to move turbines (mechanical energy) that are connected to generators. In generating the mechanical energy is transformed into electrical energy in a process close to the dynamo. This following the principle of conservation of energy, ie part of the energy used to spin the turbines is converted into electrical energy by magnetic induction.

Another way is observed in a plant, where the burning fuel produces steam that is used to move the turbines connected to generators.

The various forms of energy can be transformed into electricity, and with these changes we can use this energy in several different ways such as light (lamp), heat (shower, heaters), sound (radio).


Kinetic energy and work

We can not touch or see the energy but we can say that a body has energy when it does work and that is how we perceive it. When we lift a weight off the ground, we are doing work. The work is given by:

τ = F. d. cosθ


τ = work
F = force
d = distance
cosθ = cosine of the angle formed by the vector strength and direction of displacement

The work is also equal to change of kinetic energy, ie:

τ = ΔEc

The kinetic energy is a form of energy connected to the movement, is the energy that the bodies are due to speed and can be determined using the equation:

Ec = m.v2 / 2

Let's look at an example to illustrate the concept of kinetic energy:

We have a body of mass m = 2kg, initially at rest. This body undergoes the action of a force F = 20N and moves by a distance of force F 2m.A held a job that can be calculated by:

τ = F. d. cosθ

As the strength and distance are in the same direction, cosθ = 1, then:

τ = F. d
τ = 20. 2
τ = 40J

Now let us consider the kinetic energy of the body.

The threshold velocity of the body is zero, so its kinetic energy is also zero. Knowing that τ = ΔEc, we know where the kinetic energy of the body after covering 2m and also what will be its speed at this point.

τ = ΔEc
τ = Ec - E0
τ = Ec
Ec = 40J

To find the velocity of the body after covering the 2m, we use the kinetic energy equation:


Ec = m.v2 / 2
40 = 2. v2 / 2
40 = v2
v2 = 40


Nos next text we will see about the work and forms of energy. Before, you can see this experiment in physics, Euler's Disk, which I found in Science Tube.


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