Type of energy and energy form

There are different forms of energy as kinetic, potential, mechanical, thermal, gravitational, sound, elastic, light, and electromagnetic energy, but there are two main types of energy: 

  • potential energy - this is stored energy.
  • kinetic energy - this is moving energy.

The forms of energy are often named after a related force. Any form of energy can be transformed into another form.

kinetic energy
This is the energy of motion.
There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another).
Kinetic energy expresses the fact that a moving object can do work on anything it hits. The total mechanical energy of an object is the sum of its kinetic energy and potential energy. 
If the object is moving the kinetic energy equals one half times the mass (m) of the object times (t) the square of the speed (v) of the object: 


kinetic energy concept

Do you know why if you bike and try to stop suddenly it's not possible and it will take a few seconds to stop completely? Do you know why it's dangerous to step out suddenly on the road and why the car cannot stop immediately? This is because of the kinetic energy.
Look at the equation above. The kinetic energy depends of the mass and spped of the objective (car). Therefore of a truck and car are driving with one and the same speed the truck needs more time and distance to stop, because the truck is more heavy than the car. The same truck can do more work on you than the car.
kinetic energy of moving truck
potential energy
Potential energy results from position or configuration of the object. An object can store energy as the result of its position. The most populated example of this is the position of objects in the earth's gravitational field.
The potential energy of the object is depend of the mass of the object (m), gravitational acceleration of the earth (g=9.8 m/sec2) and objective height above earth's surface (h).
It is given by:
potential energy of bulldozer ball potential energy of a spring
mechanical energy
The energy acquired by the objects upon which work is done is known as mechanical energy. In physics, mechanical energy describes the sum of potential energy and kinetic energy present in the components of a mechanical system. Mechanical energy is the energy associated with the motion or position of an object. Mechanical energy is the ability to do work.
mechanical energy  weight lifter
By definition, work is an energy requiring process. Work is a force applied to an object over a certain distance, such as pulling or pushing a wooden block across your desk. Your muscles do work when they facilitate body movement. Units of work and energy are joules
thermal energy
Thermal energy is generated and measured by any kind of heat. Thermal energy is the total internal kinetic energy of an object due to the random motion of its atoms and molecules.
Solar thermal power and thermal power of the fire are of the most commonly used forms of thermal energy.
gravitational energy
Energy that is stored in the gravitational field is called gravitational potential energy, or potential energy due to gravity. Gravitational (or gravitational potential energy) is theenergy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s2. See potential energy.
sound energy
Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound energy is a form of mechanical energy.
elastic energy
Elastic energy is a potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring.
It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched. According to Hooke's law, the force has the form:
Heat is the quantity of energy stored or transferred by thermal vibrations of molecules. At absolute zero, a system has no heat energy.
The temperature of a system is the average vibrational energy of all the molecules within the system. The temperature of the objective depends on the masses and heat capacities of objective elements.