Science and Life Presentation- Energy

8/13/2019 Science and Life Presentation- Energy

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In the physical sciences, mechanical energy is the sum of potential

energy and kinetic energy.

* It is the energy associated with the motion and position of an object.

The law of conservation of mechanical energy states that in an isolatedsystem that is only subject to conservative forces the mechanical energy

is constant.

* If an object is moved in the opposite direction of a conservative net

force, the potential energy will increase and if the speed (not the velocity)of the object is changed, the kinetic energy of the object is changed as

well.



Example of Mechanical Energy

A satellite is orbiting the Earth only influenced by the conservativegravitational force and the mechanical energy is therefore conserved.

The satellite is accelerated towards the Earth with an acceleration

perpendicular to the velocity. Though the velocity is constantly changed

with the direction of the vector because of the acceleration vector, the

speed of the satellite is not since the magnitude of the velocity vectorremains unchanged.



* Kinetic Energy

* Potential Energy



* In physics, the kinetic energy of an object is

the energy which it possesses due to its motion.

* It is defined as the work needed to accelerate a body of a

given mass from rest to its stated velocity.

* Having gained this energy during its acceleration, the body

maintains this kinetic energy unless its speed changes.



Example of Kinetic Energy

The cars of a roller coaster reach their maximum kinetic energywhen at the bottom of their path. When they start rising, the kinetic

energy begins to be converted to gravitational potential energy. The

sum of kinetic and potential energy in the system remains constant,

ignoring losses to friction.



• In physics, potential energy is energy stored in a system of forcefully

interacting physical entities.

• The SI Unit for measuring work and energy is the Joule. Potential

energy is associated with forces that act on a body in a way that

depends only on the body's position in space.

• These forces can be represented by vector at every point in space

forming what is known as a vector field of forces, or a force field.



Example of Potential Energy

In the case of a bow and arrow, the energy is converted from thepotential energy in the archer's arm to the potential energy in the

bent limbs of the bow when the string is drawn back. When the string

is released, the potential energy in the bow limbs is transferred back

through the string to become kinetic energy in the arrow as it takes

flight.



Chemical Energy is energy stored in the bonds of chemical compounds(atoms and molecules). It is released in a chemical reaction, often producingheat as a by product (exothermic reaction).

Batteries, biomass, petroleum, natural gas, and coal are examples of stored

chemical energy. Usually, once chemical energy is released from a substance, that substance

is transformed into an entirely new substance.

For example, when an explosive goes off, chemical energy stored in it istransferred to the surroundings as thermal energy, sound energy andkinetic energy.

In the example above, notice that new compounds are formed from thebreakdown of other molecules or atoms. Chemical reaction causes that.



CHEMICAL ENERGY IN INDIA

The main objective of the Chemical Sources of Energy Programme is the development and

applications of fuel cell technology which produces electricity, water and heat through reaction

between hydrogen and oxygen.

Fuel Cells are emerging as power sources for automobiles.

The widespread use of fuel cells for power generation, transport and other applications is expected

to reduce dependence on scarce fossil fuels and help in preserving the environment.

Ongoing Projects in Fuel Cells:

Development of Direct Alcohol Fuel Cell and Test Protocols (IIT Delhi).

Solid Oxide Fuel Cells that operate directly on hydrocarbon feedstock (IIT Delhi).

Development of High performance intermediate temperature solid oxide fuel cells (IT-SOFC) by

low cost ceramic processing techniques (IMMT, Bhubaneshwar).

Design and development of Alkaline fuel cell : Scaling up from bench scale i.e. 185 W to 500W

(SICES Degree College of Arts, Science and Commerce, Ambernath (W), Mumbai).

Development of high performance direct Methanol Fuel Cell (University of Calcutta).

Development of PEM For fuel cell by plasma process (Institute of Advanced Study in Science

Technology, Guwahati).

Development of Non-fluorinated Polymeric Membrane for Direct Methanol Fuel Cell (Birla Institute

of Technology, Ranchi)



One of the oldest and most important applications of electrochemistry is to the storage

and conversion of energy.

As a galvanic cell converts chemical energy to work; similarly, an electrolytic

cell converts electrical work into chemical free energy. Devices that carry out theseconversions are called batteries.

In ordinary batteries the chemical components are contained within the device itself.

BATTERY

The term battery derives from the older use of this word to describe physical attack or

"beating"; Benjamin Franklin first applied the term to the electrical shocks that could beproduced by an array of charged glass plates. In common usage, the term "call" is often

used in place of battery. For portable and transportation applications especially, a battery

or fuel cell should store (and be able to deliver) the maximum amount of energy at the

desired rate (power level) from a device that has the smallest possible weight and

volume.



It is the energy carried by moving electrons in an electric conductor.

When electrons are forced along a path in a conducting substance such as a wire, theresult is energy called electricity.

Electrical generating plants do not create energy. They change other forms of energyinto electricity. For example, power plants can convert chemical energy stored in fuelsinto thermal energy, which evaporates water into steam, which produces mechanicalenergy as it moves through turbines. The turbines spin generators, which produce

electricity.

Electricity generation in India

India has seen excellent economic growth in the last two decades. One of the primereasons behind this is the availability of good infrastructure. Electrical energy is essentialfor industrial growth of any country. The availability of good power supply benefits almostevery sector of a nation. That is why the Government of India has given high priority tothe power sector of the nation. India has a flourishing power sector that is meeting mostof the energy needs of the country.The 21st century finds a huge number of electric power plants located across India. Indiahas sufficient technology and expertise to generate electricity through the use of

Coal power

Wind power

Water power

Nuclear power



State Per capita Consumption(kWh) Andaman and Nicobar Islands 506.13

Andhra Pradesh 1013.74 Arunachal Pradesh 503.27 Assam 209.2 Bihar 117.48 Chandigarh 1238.51 Delhi 1447.72 Goa 2004.77 Gujarat 1558. Haryana 1491.37 Himachal Pradesh 1144.94 Jammu & Kashmir 968.47 Jharkhand 750.46



Karnataka 855 Kerala 536.78 Lakshadweep 428.81 Madhya Pradesh 618.1 Maharashtra 1054.1 Manipur 207.15 Meghalaya 613.36 Mizoram 429.31 Nagaland

242.39

Orissa 837.55 Puducherry 1864.5 Punjab 1663.01 Rajasthan 811.12 Sikkim 845.4 Tamil Nadu 1250.81 Tripura 253.78 Uttar Pradesh 386.93 Uttarakhand 930.41 West Bengal 515.08

Average 853.05



It is not a state function i.e. it depends on the path.

Thus, absolute measurement holds no value and only change in energy is

measured. Specific heat is the amount of heat per unit mass required to raise the

temperature by one degree Celsius.

To calculate change in thermal energy=

= m x T x Cp



The ultimate source of thermal energy- Sun radiation- Geothermal energy.

Largest five geothermal plants in the world:

Country Capacity(MW)2013

USA 3389

Philippines 1894

Indonesia 1333

Mexico 980

Italy 901



• Conduction or Diffusion

- The transfer of energy between objects that are in

physical contact.• Convection

- The transfer of energy between an object and itsenvironment, due to fluid motion.

• Radiation

- The transfer of energy to or from a body by meansof the emission or absorption of electromagneticradiation.











Microwave ovens:

Penetrate food and vibrate

water & fat molecules to

produce thermal energy

Wavelengths ranging from as long as onemeter to as short as one millimeter.



• Slightly lower energy than

visible light

• Can raise the thermal

energy of objects

•

Thermogram - imagemade by detecting IR

radiation



•

*Small part of the EM spectrum we

can see.

*ROY G. BIV - colors in order ofincreasing energy

R O Y G

.

B I V

re

d

orang

e

yello

w

gree

n

blu

e

indig

o

viol

et



• Slightly higher energy

than visible light.

• Types:

• UVA - tanning, wrinkles

• UVB – sunburn, cancer

• UVC - most harmful,

sterilization



• Energy higher than UV

•

Can penetrate softtissue, but not bones



• Highest energy

EM radiation

• Emitted by

radioactive

atoms

• Used to kill

cancerous cells Radiation treatment

using radioactive

cobalt-60.



• A non renewableenergy resource is a

resource that does notrenew itself at asufficient rate forsustainable economicextraction in

meaningful humantime frames. Fossilfuels, metal ores are theexamples of theseresources.



• Fossil fuels arehydrocarbons,primarily coal formedfrom the remains of

dead plants andanimals. Coal, oil andgas are called fossilfuels because they havebeen formed from the

organic remains ofprehistoric plants andanimals.



1. Coal

2. Natural gas

3. Oil4. Petroleum

5. Liquefied

petroleum gas(LPG)

http://www.petroleum.co.uk/



• It is the energy thatis trapped insideeach atom. Any

change occurring inthe nuclear structure which results in theliberation of high

amounts of energy iscalled nuclearenergy.



• The process in which two nuclei

fuse together,forming anothernucleus is callednuclear fusion. Thisprocess generallyreleases a largeamount of energy.



• Vast amounts of energyare liberated using theprocesses in which anunstable heavy nucleus

splits apart into smallernuclei, this is callednuclear fission.

Example- Uranium

nuclei break apart intosmaller nuclei whilesimultaneouslyreleasing energy.



• Energy sources that can begenerated using naturally occurringphenomena are known as

renewable energy sources.

• Various forms of renewable energy

sources are solar, wind, biomass, hydro,geothermal, wave and tidal energy.



It refers primarily to the use of solar radiationfor practical ends

Sunlight and heat is the source of source of

solar energy This can be used in solar water heaters, solar

cookers and solar electric generators

The total solar energy absorbed by earth’satmosphere, oceans and land masses isapproximately 3850000 exajoules (EX) per year



It involves harnessing of wind power toproduce electricity

In order to make a wind system effective, aconsistent average wind speed of 25-30km/h is required

Worldwide there are now over two

hundread thousand wind turbinesoperating



It is a renewable energy resource derived fromthe carbonaceous waste of various human andnatural sources called biomass

These include byproducts from the woodindustry, agricultural crops and raw materialsfrom the forest, household wastes and so on

Biomass can be converted into liquid fuelssuch as ethanol and biodiesel which are usedto fuel our transportation needs



• It is the term referring to energy generated byhydro power i.e the production of electricalpower through the use of gravitational force offalling water

• It accounts for 16% of global electricitygeneration

• Three Gorges Dam in the Peoples Republic OfChina is the largest hydroelectric power station

in the world• India is the 7th largest hydroenergy producer in

the world



It is the thermal energy generated and storedin the earth

Water is pumped in the ground where it comes

into contact with the hot rocks present belowthe earth’s surface. This leads to thetransformation of water into steam which isfurther used to generate electric energy

The largest group of geothermal power plantsin the world is located at the Geysers, ageothermal field in california



It is a form of hydropower that converts theenergy of tides into useful forms of power-mainly electricity

However there are some tidal power issuesrelated such as:

1) Tidal power can have effects on marine life

2) Salt water causes corrosion in metal parts





*In physics, the law of conservation of energy states that thetotal energy of an isolated system cannot change—it is said to

be conserved over time.

*Energy can be neither created nor destroyed, but can

change form.

*For instance chemical energy can be converted to kinetic

energy in the explosion of a stick of dynamite.

*A consequence of the law of conservation of energy is that

a perpetual motion machine of the first kind cannot exist. That isto say, no system without an external energy supply can deliver

an unlimited amount of energy to its surroundings.



The law of conservation of energy can be seen in these everyday examples of energy

transference:

Water can produce electricity. Water falls from the sky, converting potential energy to

kinetic energy. This energy is then used to rotate the turbine of a generator to produce

electricity. In this process, the potential energy of water in a dam can be turned intokinetic energy which can then become electric energy.

When a moving car hits a parked car and causes the parked car to move, energy is

transferred from the moving car to the parked car.

A fly ball hits a window in a house, shattering the glass. The energy from the ball was

transferred to the glass, making it shatter into pieces and fly in various directions.

Two football players collided on the field, and both went flying backwards. Energy wastransferred from each player to the other, sending them in the opposite direction from

which they had been running.

Potential energy of oil or gas is changed into energy to heat a building.



*Energy in a system may take on variousforms (e.g. kinetic, potential, heat, light).

*The law of conservation of energy states

that energy may neither be created nordestroyed.

*Therefore the sum of all the energies in the

system is a constant.



The most commonly used example is the pendulum:

The formula to calculate the potential energy is:

PE = mgh

The mass of the ball = 10kg The height, h = 0.2m

The acceleration due to gravity, g = 9.8 m/s^2

Substitute the values into the formula and you get:

PE = 19.6J (J = Joules, unit of energy)

The position of the blue ball is where the Potential Energy (PE) = 19.6J while the Kinetic Energy

(KE) = 0.

As the blue ball is approaching the purple ball position the PE is decreasing while the KE is

increasing. At exactly halfway between the blue and purple ball position the PE = KE. The position of the purple ball is where the Kinetic Energy is at its maximum while

the Potential Energy (PE) = 0.

At this point, theoretically, all the PE has transformed into KE> Therefore now the KE =

19.6J while the PE = 0.

The position of the pink ball is where the Potential Energy (PE) is once again at

its maximum and the Kinetic Energy (KE) = 0.

We can now say and understand that:PE + KE = 0

PE = -KE

The sum of PE and KE is the total mechanical energy:

Total Mechanical Energy = PE + KE

NOTE: This is with the absence of outside forces such as friction



There are many ways in which each individual can help conserve energy:

*This can be done by turning off the lights, fan, air conditioners and other

electrical appliances when not in use.

*Setting the thermostat of ACs one or two degrees lower during winters and

one or two degrees higher in summers can reduce energy by a significant

amount.

*Car pooling or using public transportation will reduce the fuel or energy

consumption.



Group Members: Aditi Bairathi 130607

Aditi Kaushik 130549 Akanksha Sharma 130821 Anjali Lal 130906 Archana Jain 130546

Arunima Malik 130746Presentation compiled by Akanksha Sharma

Science and Life Presentation- Energy

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