Presentation Energy, Force and Motion- Irene Lim Dacles

8/8/2019 Presentation Energy, Force and Motion- Irene Lim Dacles

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4. The energy of position is calledA. radiant energy C. potential energy

B. stationary energy D. kinetic energy

5. Acceleration is the change of velocity over a giventime. A car has an acceleration of 1 m/s. What is thechange in its velocity after every 3 seconds.

A. 3 m/s D. 1 m/sB 2 m/s E. 4 m/s

C. 0 m/s

6. Objects seem to be heavier on Earth than on moon.

A. Earth has more mass than moon.

B. the moon has no atmosphere unlike in EarthC. Earth is nearer to the sun the moon in most of thetime.

D. theres no waterin the moon

E.Earth hasstrongergravitational pull than the moon.


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7. Runners crossing the finish line of a race often take time before

they completely stop.A. Law of Acceleration D. Law of Conservation

of Energy

B. Law of Inertia E. Theory of Relativity

C. Law of Conservation of Momentum

8. An electric motor is a device that changes:

A. magnetic field producing electricity

B. electric energy into mechanical energy

C. chemical energy into electric energy

D. potential energy into electric energyE. Kinetic energy into electric energy


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9. Compared to radio waves, infrared rays have;

A. shorter wavelength, but higher frequency

B. shorter wavelength and lower frequency

C. longer wavelength and longer frequency

D. shorter wavelength , but the same frequency

10. Which of the following is an example of Newtonssecond law of motion.

1. A parked vehicle.

11. A basketball player throwing a ball.

111. A seat belt preventing a passenger from hittingthe windshield.

A. 1 only D. 1 and 11B. 11 only E. 11 and 111

C. 111 only


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By: IRENE LIM DACLES


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ENERGY

Different Forms of

Energy and Energy

Conversions

Energy can be

conserved.

Potential EnergyKinetic Energy

Mass Velocity

Is affected by

Weight Gravity

Is affected by

Sources/

Alternative

Sources of

Energy

Two Types of Energy


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EnergyEnergyy is defined as the capacity to do work. No matter how easy

or difficult any work maybe, an object cannot do workwithout energy.

y Energy lights our cities, powers our cars, jeeps, buses,trains, planes and rockets. Energy warms our homes, cooksour food, plays our music, sends our text messages andgives us pictures on television. It also powers machinery infactories and tractors on a farm.

y Energy from the sun gives us light during the day. It driesour clothes and helps plants to grow. Energy stored inplants serves as energy for plant-eating animals whichserve as their energy source.


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Kinetic

Energy

PotentialEnergy

is the energy an object hasbecause of its motion. It isdependent on mass andvelocity of the object.ofwaves, electrons, atoms,molecules, substances, andobjects.

is a stored energy and theenergy of position. It is

dependent on its mass, theacceleration due to gravity andits height from the ground.


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Law of Conservation of Energy

Energy is not currently being created. The universe could nothave created itselfusing natural processes because nature did not

exist before the universe came into existence. Something beyond

nature must have created all the energy and matter that is observed

today. Present measures ofenergy are immeasurably enormous,

indicating a powersource so great that "infinite" is the best word we

have to describe it.Energy is neverlost. Ifenergy seems to disappear,it just must be somewhere!

The logical conclusion is that oursupernatural Creatorwith

infinite powercreated the universe. There is no energy source capable

to originate what we observe today.

Energy Cannot Naturally BeCreated or Destroyed ; It can

only Be Changed from One Form

to Another.


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FORMS OF ENERGY ( kinetic)

Electrical Energy is the movement ofelectrical charges.Everything is made

oftiny p

artic

les

call

edatom

s.Atom

sar

e made o

feven

sm

aller

par

ticles

call

edelectrons, protons,and neutrons. Applying aforce can make some of theelectrons move.Electrical charges moving through a wire is called electricity.Lightning isanotherexample ofelectrical energy.

Radiant Energy is electromagnetic energy that travels in transverse waves.Radiant energy includesvisible light, x-rays, gammaraysand radio waves.Light is one type ofradiant energy. Solarenergy isan example ofradiantenergy.

Thermal Energy, orheat, is the internal energy in substancesthe vibrationand movement of the atomsand molecules within substances. Geothermalenergy isan example of thermal energy.

Mechanical Energy/Motion Energy is the movement ofobjectsandsubstancesfrom one place to another. Objectsand substances move when aforce isapplied according to Newtons Laws ofMotion. Wind isan example ofmotion energy.

Sound Energy is the movement ofenergy through substances in longitudinal(compression/rarefaction) waves. Sound is produced when aforce causesanobject orsubstance to vibratethe energy is transferred through thesubstance in a wave.

Heat Energy is the energy produced by the motion ofmolecules in asubstance. The faster the particles move, the more heat energy is produced.

Wind energy maybe harnessed trough the used ofwindmills. Windmillsaredevices used to make the energy ofmoving airorwind to do work


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FORMS OF ENERGY (Potential)

Chemical Energy is energy stored in the bonds ofatomsandmolecules. It is the energy that holds these particles together.Biomass, petroleum, natural gas,and propane are examples ofstored chemical energy.

Stored Mechanical Energy is energy stored in objects by theapplication ofaforce. Compressed springsand stretchedrubberbandsare examples ofstored mechanical energy.

Nuclear Energy is energy stored in the nucleus ofan atom

the energy that holds the nucleus together. The energy can bereleased when the nuclei are combined orsplit apart. Nuclearpowerplantssplit the nuclei ofuranium atoms in a processcalled fission. The sun combines the nuclei ofhydrogen atomsin a process called fusion. Scientistsare working on creatingfusion energy on earth,so that someday there might be fusionpowerplants.

Gravitational Energy is the energy ofposition orplace. A rockresting at the top ofa hill contains gravitational potential energy.

Hydropower,such as water in areservoirbehind a dam, isanexample ofgravitational potential energy.

Geothermal Energy isa heat tapped from below the Earthssurface. It is in the form ofsteam which is piped into generatorsto produce electricity.


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It is the process of changing energy from one formto another. This process is happening all the time, bothin the world and within people. When people consume

food, the body utilizes the chemical energy in thebonds of the food and transforms it intomechanical energy, a new form of chemical energy, orthermal energy. Energy transformation is an importantconcept in the application of the physical sciences. Theability for energy to be transformed automates, lights,entertains, and warms the world in an astoundingmultitude of ways.


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Examples of sets of energy conversions

in machines

For instance, a coal-fired power plant involves thesepower transfers:

Chemical energy in the coal converted to thermal

energy Thermal energy converted to kinetic

energy in steam

Kinetic energy converted to mechanical energy in

the turbine Mechanical energy of the turbine converted to

electrical energy, which is the ultimate output

For instance, a coal-fired power plant involves thesepower transfers:

Chemical energy in the coal converted to thermal

energy Thermal energy converted to kinetic

energy in steam

Kinetic energy converted to mechanical energy in

the turbine Mechanical energy of the turbine converted to

electrical energy, which is the ultimate output


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Type of Device From To

. Battery chemical energy electrical energy

2. Guitar mechanical energy sound energy

3. Motor electrical energy mechanical energy

4. Flat Iron electrical energy heat energy

5. Food Processor electrical energy mechanical energy

6. Television electrical energy light energy, soundenergy + heat


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y Sources of Energyy 1.Conventional (Nonrenewable) Sources of Energyy Most of the energy we use comes from fossil fuels,

such as coal, natural gas and petroleum. Fossil fuels areformed from plants and animals that lived up to 300 millionyears ago, fossil fuels are found in deposits beneath theearth. The fuels are burned to release the chemical energythat is stored within this resource. Energy is essential tomodern society as we know it. Over 85% of our energy

demands are met by the combustion of fossil fuels.Uranium is another nonrenewable source, but it is not afossil fuel. Uranium is converted to a fuel and used innuclear power plants. Once these natural resources areused up, they are gone forever.

y The process of gathering these fuels can be harmful to thebiomes from which they come. Fossil fuels are put through

a process called combustion in order to produce energy.Combustion releases pollution, such as carbon monoxideand sulfur dioxide, which may contribute to acid rain andglobal warming.


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2. Alternative Sources (Renewable) Sources of EnergyRenewable sources of energy can be used over and

over again. Renewable resources include solar energy,wind, geothermal energy, biomass and hydropower. Theygenerate much less pollution, both in gathering andproduction, than nonrenewable sources.

Solar energy comes from the sun. Some people use solarpanels on their homes to convert sunlight into electricity.

Wind turbines, which look like giant windmills, generate

electricity.Geothermal energy comes from the Earth's crust.Engineers extract steam or very hot water from the Earth'scrust and use the steam to generate electricity.

Biomass includes natural products such as wood, manureand corn. These materials are burned and used for heat.

Hydroelectric Energy Dams and rivers generatehydropower. When water flows through a dam it activates aturbine, which runs an electric generator.

Tidal Energy - power from tidal currents and wavemotion (Types of Environmentally Friendly Fuels)


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Newtons

Law of

Motion

ForceA push or pull

Contact ForcesNoncontact Forces

Motion

AppliedFrictionalNuclearElectromagneticGravitational

Electric Magnetic Static,rolling,sliding

no direction

indicated

Speed (v)

Distance (d)

Time (t)

direction is

indicated

elocity (v)Displacement (d)

Time (t)

Acceleration

change in

velocity per unit

time

Normal


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is a push or pull causing an object to start moving or changingitsstate of rest. Forces can be balanced or unbalanced. Balancedforcesdo not cause a change in motion; they are equal insize andopposite in direction. Unlike balanced forces, unbalanced forcesalways cause a change in motion; they are not equal insize andopposite in direction. When two unbalanced forces are exerted inopposite directions, their combined force is equal to the differencebetween the two forces, and is exerted in the directionof the largerforce. Unbalanced forces can also be exerted in the same direction.If a force twists an object,it is called torsion (massage). The forcethat stretches an object is called tension (rope or rubberband)


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TYPES OF FORCES

Frictional

Applied

Gravitational

Electromagnetic

Nuclear

Normal


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Forces cause motion. Motion is allaround us. Motion can be describedthrough its speed as fast or slow. Motionis a change in position of an object withrespect to a fixed reference point.


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Speedis the term used to describe the distance travelled per

unit of time.Speed = distance Given

time d = 3kmv = d t = 5 hrs

t Solutionv = d

tv = 3 km

5hv = 0.6 km

h

Ifyou need to solve fordistance (d):

distance= speed x timed = v x t

Ifyou need to solve for time (t):

time = distance

speed

t = d

v


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issimilar to speed except that it only tellshow fast or howslow motionis,it also indicates the direction. Velocityis a vectorquantityin that it has both magnitude and direction,speed is ascalar quantity,it onlyhas magnitude. Hence, velocityis

calculated as:Wherevis the velocity,d is the displacement,t is the time.

Displacement indicates both the distance and direction ofmotion.

Example: A Philippine Air Lines plane takes off from Manila at 5:30a.m. and is expected to land in Zamboanga,854 km. south ofManila at exactly 7:00 a.m.. What should the average velocity of

the plane be ifit is to land in Zamboanga City on time?


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Given:d= 852 km,south

t = 1 hour and 30 minutes or 1.5 hours

Solution

velocity = Ifyou need to solve fordisplacement (d):

displacement = velocity x time

d= vx t


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is defined as the rate of change of velocity and is measured inmeters/centimetres per second per second (m/s2), (cm/s2).

A falling ball accelerates toward the ground as gravity pulls itdownward. Gravity exerts an acceleration of 9.8 m/s2 that is

to say, the velocity of the falling ball increases by 9.8 m/s everysecond, and so on. Physicists found the constant value 9.8m/s2 due to Earths gravity.

Acceleration is said to be positive if the velocity increases;negative if velocity decreases; or zero if there is no change in

velocity. A car is accelerating if the speed increases and brakingor decelerating when the speed decreases. The acceleration ofthe car moving at the constant speed is equal to zero becausethere is no change in speed.


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Acceleration is calculated as:

Acceleration=

where

a = acceleration

= final velocity= initial velocity

t = time


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Sample ProblemMartin rides a bicycle at 7 m/s. Tenseconds later,he isdriving at 10 m/s. What is Martins acceleration?

Given

= 7 m/s

= 10 m/s

t = 10 s


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Solution

Martin is driving at .


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MASSAND WEIGHT

Th

e concepts ofmass and weight are not th

e same. Every ph

ysicalbody has an inherent property called its mass. Mass may most simply be

considered as the amount of matter in any object.

Gravitygives us our weight, the larger the gravitational force the

'heavier' we are. Weight is simply a measure of the force of gravity acting on

a body, and this varies depending on the strength of that force. A fleaweighs more on Earth than on our much less massive Moon. That is why it

could jump muchhigher on the Moon than on the Earth. Its mass, however,

will remain the same anywhere in the universe.

In the universe there are many objects with a much larger mass than

Earth. In neutron stars, for instance, all matter is so densely packed that

their mass is billions of times largerthan the Earth's, and so is their gravity.On the surface of this type of star the flea would weigh thousands of tons,

and would be crushed by its own weight and could not even attempt to

jump.

Black holes are even more dense, their gravity even pulls light back

towards its surface.


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1. Law of Inertia (inertia is a body's resistance toacceleration):An object at rest tends to stay at rest, andan object inmotion tends to stay in motion with the same speedandin the same direction unless actedupon by anoutside force.

Examples: Forces acting on a book are opposing but equal in magnitude. (book-equilibrium)

Vehicular collisions .

Seatbelts provide the unbalanced force to prevent the passengers from hitting the windshield.


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2. Law of Motion or Law ofAcceleration

An object will onlyaccelerate if there is a net orunbalanced force acting uponit.

The presence ofunbalanced force willaccelerate an object- changingits speed or its direction, orboth its speed and direction.

Example: The stronger the engine of a car, thefaster it accelerates, but the heavier the car,

the slower it accelerates (with the sameengine).If the baseball player hits the ball

with a greater force, the ball will acceleratein the direction of the force with greater

speed and vice versa.


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3. Law of Reaction or Interaction

Every action, creates an equal and oppositereaction.

Example: The wheels of a vehicle actually spin backward and the road reacts bypushing the wheels forward.

Boy scouts pulling a rope attached to a tree.


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THE ENDTHE END

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Presentation Energy, Force and Motion- Irene Lim Dacles

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