Different Types of Enery

8/13/2019 Different Types of Enery

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What is energy?

There is no single definition of energy. The word energy has different meanings. In daily

usage, energy refers to sources of fuel. Thus, we use the term “energy” to mean food, gasoline,

coal, geothermal, electricity, and solar. Often, we say, we need energy to perform our daily

activities or a bus needs energy to run.

Energy can do useful things. It is likened to money. Having a lot of energy is like having

plenty of money. But having money is not enough to do useful things. Money should be handed

over to another person so it can do something. Energy is also like this. It needs to be transferred toanother body so it can do something useful.

When a power plant produces electrical energy, this energy is transferred to the

transmission line, to the household lines, and finally, to the appliances and lamps in our homes.

The lamp produces light and the cooking appliance produces heat to cook our food.

When you lift an object, the energy from your body is used up. In this way you lose

chemical energy while the object gains gravitational potential energy. Energy is transferred from

your body to the object.



Since we already mention energy transfer, these are the examples:

Work is the product of an external force (F) applied on the

object and the distance (d) it travels in the direction of force.

W= Fd

The unit of work may be expressed in Newton-meter (N.m) or Joule (J).

Doing work on a body, like lifting it to a higher level or pushing it to move, results in an

energy increase or energy change in body. Hence, work can be expressed as:

W=▲E or W=Change in energy

Although energy and work are related, they are not exactly the same. Work is not energy

but a method of transferring energy. When work is done, energy is transferred. The body doing a

work loses energy while the body on which the work is done gains energy.

Cars run due to energy transfer. Gasoline is burned inside the car engine. As a result,

expanding gases in the engine push to the piston and do work on it. The piston then transfers

energy to the wheels of the car.

Example:

F= 50N

d=2m

______________________

Then, the work will be W= 50N x 2m, which is equal to W=100J



Types of energy:

Mechanical Energy: this is energy in motion that does the work.

Heat Energy: this is where motion or rise in temperature is caused by heat.

Chemical Energy: this where chemical reaction casing changes.

Electrical Energy: this is when light, motion or heat is produced by electric

current

Gravitational Energy: this is when motion is caused by the gravitational

pull



Potential Energy:

It is energy at rest.

A system that is due to the position of the body or arrangement of particle in the body.

Suppose an object with mass is lifted up to a height at constant speed. The force applied on the

object is equal to the weight of the object or

F= mag, where ag is the acceleration due to gravity. The work done on the object is W= F x

h.

Hence, the work done is W=magh.

If the object stays at rest at its new position, the work done will represent the change in

gravitational potential energy. In equation:

▲(PE)grav = (PEgrav)final-(PEgrav)initial or

= (magh)final- (magh)initial

If the gravitational potential energy of the object at its initial position is zero, then its final

gravitational energy can be written as:

▲(PE)grav = magh

The gravitational potential energy of an object is considered relative to a reference position.

Oftentimes, the gravitational potential energy at the reference position is assumed to be zero.



In this example, assume that he is doing some tricks. He will

try to jump over the stall chair. Before jumping, he ran faster

so he can jump on time. That moment, it created a kinetic

energy which is equal to 3000 J. And when the moment he

jumped over the stall chair, the kinetic energy decreases

because it transformed to potential energy. Potential energy

increases until it reaches the peak and it will decrease when

he’s landing on the ground.



A body with gravitational potential energy can do work. Consider the image shown above. When

car B rolls down the ramp, the car’s potential energy is transformed to kinetic energy. When it

reaches the bottom of the ramp, car B does work on car A as it pushes car A through a distance.

Thus, car A gains energy, while car B loses energy.

Types of Potential Energy

force field quantity in field examples and subtypes

gravitational massroller coaster, waterwheel,

hydroelectric reservoir,…

electromagnetic charge electric, magnetic, chemical, elastic,

strong nuclear color charge nuclear reactors, nuclear weapons,

weak nuclear lepton number radioactive decay



There are other forms of potential energy. When you compress or stretch a spring, for instance,

you also do work. This work changes the spring’s elastic potential energy. If you release the

spring, it will start to vibrate, changing its potential energy to kinetic energy.



Bibliography:

http://www.launc.tased.edu.au/online/sciences/PhysSci/done/kinetics/wep/Work.htm

http://physics.info/energy/

http://powermin.nic.in/kids/types_of_energy.htm

http://en.wikipedia.org/wiki/Potential_energy

Physics Textbook (Department of Education)













Different Types of Enery

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