ENERGY TRANSFORMATIONS

There are various forms of energy, for example:

-A battery contains chemical energy which is transformed into electrical energy. Then a lightbulb transforms the electrical current into luminous and thermal energy.

-The chemical energy in our muscles can be transformed into mechanical energy in order to move objects.

-The chemical energy can be stored in fireworks.

When fireworks explode, that chemical energy is converted into light, heat, sound and mechanical energy.

-Photovoltaic solar panels transforms luminous energy into electrical energy.

-Internal combustion engines transform the chemical energy of fossil fuels into thermal energy. Most of this thermal energy is transformed into motion , but some is lost as heat.

Some energy is also lost as sound.

-A kitchen mixer converts electrical energy into kinetic energy to turn the machine's axis. Some energy is also lost as heat.

-In stars, the nuclear energy of atoms, is transformed into very intense luminous and thermal energy.

ENERGY CAN BE TRANSFORMED, BUT IT CANNOT BE CREATE OR DESTROYED. THIS IS THE THE PRINCIPLE OF ENERGY CONSERVATION.

UNITS OF MEASUREMENT FOR ENERGY AND POWER

In the International System, energy is measured in joules.
When energy takes the form of heat, we often express it as calories.
The relationship between calories and joules is: 1 cal = 4.18 J.
 POWER.
Power is a measurement of how quickly work is done.
The power of a machine is the amount of work that it can do in a certain amount of time.
We express this relationship as: P = W/t
P: POWER.
W: AMOUNT OF WORK.
T: TIME.
The relationship between input and output energy in any machine is expressed as its energy conversion efficiency:
Energy conversion efficiency (%) = output/input x 100

FORMS OF ENERGY

Some form of energy is present in all physical phenomena.
-POTENTIAL ENERGY: associated with the height of an object above the ground, or the storage of energy in a spring.
-KINETIC ENERGY: the energy of physical movement.
-MECHANICAL ENERGY: the sum of potential and kinetic energy.
-SOUND ENERGY: the energy of sound waves, which are produced by vibrations and propagated through a physical medium.
-ELECTRICAL ENERGY: the product of an electrical current.
-NUCLEAR ENERGY: the energy in the nucleus of an atom.
-LUMINOUS ENERGY: associated with light.
-THERMAL OR CALORIFIC ENERGY: associated with the movement of particles in matter.
-CHEMICAL ENERGY: results from the formation or descomposition of substances.
-ELECTROMAGNETIC ENERGY: occurs when electrical currents create magnetic fields.
  LUMINOUS ENERGY

ENERGY.

Energy is the capacity of a body to perform transformations and do work.
In prehistoric times, muscular energy was the only source of energy that people had. Then different mechanisms and machines were invented to make everyday tasks easier and improve people's quality of life.