Target 1: Identify how force, energy and work relate to each other

What is a force?

• A force is anything that can put matter in motion, which is a push or pull in any direction.

Balanced forces

• Balanced forces occur when forces are equal in size and opposite in direction. As a result an object’s motion will not be affected (object stays at rest or continues moving at the same speed and direction)

Or

The forces are equal so the ball won’t move.

Unbalanced Forces

• Unbalanced forces are unequal and not always opposite. They result in a change in motion (slow down, speed up)

The forces are unequal so the ball will move

What is motion?

• Motion refers to the change in the position of an object over a period of time. Motion consists of both speed and direction (north, south, east, west)

• Speed (Velocity) is the distance traveled over a period of time.

• Speed = distance/time

What is work?

• Work is using a force to move an object. If the object does not move then no work is done.

• How do we make work easier?

What is energy?

• Energy is the ability to do work.

• Why is energy so important????• Energy provides the ability to exert a force,

which can result in the accomplishment of work. Give an example! (boil water, push car)

Target 2: What is mechanical energy?

• Mechanical energy is the energy that is possessed by an object due to its motion or due to its position. Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position). Or a combination of both.

Target 2: The energy of different objects may fall into two main categories: Kinetic Energy and Potential Energy

Potential EnergyPotential Energy is stored energy. This can be thought of in two ways. the energy stored in elastic materials as the result of their stretching or compressing is elastic potential energy. Stored energy due to the position of an object above the surface of the earth is gravitational potential energy.

Kinetic Energy• Kinetic Energy is the energy of a moving

object it depends upon two factors: the mass of the object and its velocity (speed).

The Ball

PotentialEnergy

KineticEnergy

PotentialEnergy

KineticEnergy

PotentialEnergy

KineticEnergy

PotentialEnergy

KineticEnergy

PotentialEnergy

KineticEnergy

Electrical Energy• Electrical Energy is the movement of

electrons from one substance to another

Thermal Energy

• Thermal Energy (heat) is the total amount of energy from the vibration of particles (atoms) in matter

• Thermal Energy affects how fast atoms vibrate. Increasing thermal energy increases the speed of the atoms. vibrating particles possess kinetic energy.

• Temperature is the measure of thermal energy

Chemical Energy

• Chemical Energy is the amount of energy stored in compounds and molecules. When chemical bonds break, the energy is released.

• Ex: When wood or gasoline burns, chemical energy is converted into heat. The energy used by cells in your body comes from chemical energy stored in the foods we eat.

Target 4: What is the Law of Conservation of Energy?

Energy cannot be created nor destroyed….but….

Energy can be transformed from one type to another.

In this diagram, electrical energy is converted into thermal (heat) energy and light energy.

Objects can convert potential energy to kinetic energy or kinetic energy to potential energy.

The diagram below illustrates this relationship.

How does stored water change forms of energy?

• Water is behind the dam (gravitational potential). • Water flows downward (kinetic) and forces a turbine to

move (kinetic). • The kinetic energy is converted into electrical energy by

generators.

http://www.brainpop.com/technology/scienceandindustry/dams/

Energy Efficiency

• Energy efficiency is the measurement of usable energy after an energy conversion.

clothes washer efficiencyenergy loss for lighting

•Energy is being converted from chemical to kinetic•The goal is to convert 100% of the chemical energy to kinetic.

•What happened to some of the energy in the conversion?

Incandescent VS FluorescentThe Difference - TechnologyThe key difference between Fluorescents and Incandescents is how they "create" light. Fluorescent bulbs outlast up to 13 incandescent or halogen bulbs.

The Difference - CostCheck the Facts! A compact fluorescent may cost more to purchase than an incandescent, but that's where the story ends. Compacts can typically save 8 to 12 times their cost.

The Difference – Temperature90% of the energy consumed by an incandescent bulb is wasted heat. This makes the bulb extremely hot to touch and very unsafe.

Explain paths of Seismic Waves.

1. P waves - creates the big band sound, fastest wave first to travel and is a compression wave.

2. S waves - are transverse waves with an up and down motion.

3. L waves - most destructive waves are last to hit and result in a rolling motion.

Target 5: Explain that forms of energy can travel in waves

What is an energy wave?

• A wave is a vibration that carries energy through matter or space.

• The wave moves outward from the source of energy in all directions. The matter does not move but the energy does.

What are seismic waves?• Seismic waves occur when rocks in the Earth’s

crust break at fault lines. This event is known as an earthquake.

• Seismic waves are vibrations that spread out from the focus(area where the rocks break) in all directions.

ttp://earthquakes.tafoni.net/

http://www.edumedia-sciences.com/a89_l2-the-3-types-of-seismic-waves.html

What are sound waves?

• Sound waves are caused by vibrations. They are waves of energy which spread out in all directions from the source of sound production.

• Sound waves can travel through solids, liquids and gasses (travel fastest through solids).

• Human brains can detect the vibrations and form an understanding of the vibrations. The vibrations are known as sound

Target 6: What are nonrenewable energy resources?

• They are resources that are being used faster than Earth processes can replace them.

• Nonrenewable resources include fossil fuels which are formed from the remains of buried plants and other organisms that have been altered over millions of years

http://www.brainpop.com/science/energy/energysources/

What are the different fossil fuels and their uses?

Coal •Generate electricity

Natural Gas •Heat buildings•Source of sulfur

Oil •Produce gasoline or other fuels•Lubricant•Make into plastics, home shingles and other products

What is coal?

• Most abundant fossil fuel• Run out in 250 years• Contains at least 50% plant remains• Begins to form when plants die in a swampy area.• Takes millions of years to form

The map below shows areas of coal deposits in the United States.

What are the stages of coal formation?

2. Compaction forces water out of the sediments to form lignite, a soft, brown coal.

1. Plant materials buried under sediments decay to form peat, a compressed mass of plant remains.

Forming of coal!

3. Further compression and aging turn lignite into bituminous coal, a soft, black coal.

4. Heat and pressure metamorphose bituminous coal to anthracite, a hard coal that is almost pure carbon.

How does oil and natural gas form?• Remains of marine life in ocean sediment

• Takes millions of years to form

• Similar process as coal

• Are forced upward becausethey are less dense than water

• Rocks such as shale trapthe oil and gas

• Comprised of hydrogen and carbon compounds

Conserving fossil fuels• Roughly 87% of the United States’ energy supply comes from fossil

fuels. – 41% comes from petroleum

• Fossil fuels are being used much faster than they are replenished

• What can be done to conserve fossil fuels so we do not run out?

– Energy Hogs unit• Computer tutorial• In-class lesson• Weekend activity

http://www.brainpop.com/science/energy/fossilfuels/

http://www.msnbc.msn.com/id/21468803/wid/21370087/

What is nuclear fission

Splitting Uranium atoms (breaking apart the nucleus) to produce thermal energy and ultimately elctricity

Benefit -does not contribute to global warming or air pollution

Problems - Produces radioactive wastes, disposal problems and meltdowns

How does nuclear fission produce electricity?

1. Neutrons are fired into Uranium -235 atoms2. The atoms break apart and fire off more

neutrons which in turn split more U-235 atoms3. A chain reaction has begun.4. Every time an atom splits heat energy is

released.5. The heat boils water to make steam.6. The steam turns a turbine, which turns a

generator that produces electricity.

Fission to electricity continued

http://www.brainpop.com/science/energy/nuclearenergy/

Nuclear reactor sites

Maps showing Nuclear Power Plants in each State

VIII. What are waste products of fission?

• Radioactive waste is produced from nuclear fission. (isotopes of Barium, Krypton and Zirconium).

• Yucca Mountain

• The waste can remain radioactive for thousands of years

http://www.yuccamountain.org/usamap1.gif

http://www.brainpop.com/science/energy/radioactivity/

What are renewable energy resources?

• They are energy resources that are being replaced as fast as being used1. Solar2. Wind3. Hydroelectric4. Geothermal5. Biomass

What is the problemwith this graph?

Where does your energy come from?

What is solar energy?

– It is energy from the sun!– Collect the energy with solar cells and convert it to

electricity– positives: renewable, no pollution, does not

contribute to global warming– negatives: difficult to utilize on cloudy days and at night.

Expensive to purchase.

http://www.brainpop.com/search/?keyword=solar+energy

What is wind energy?• Energy from wind• wind rotates the blades of a windmill. The blades

(turbines) rotate a generator to produce electricity.• positives: renewable, no pollution, does not contribute

to global warming• negatives: wind is not always steady, kills birds,

unsightly, take up space

What is hydroelectric energy?• It is electricity that is produced by water power• Water is released from dams. The force of the water

turns the turbine. The turbines turn generators that make electricity.

• positives: renewable, no pollution, does not contribute to global warming

• negatives: land above that dam is flooded, which damages habitats. The lakes created from the dam fill with sediment, which damages fish populations. If breaks will flood a lot of area

http://www.brainpop.com/technology/scienceandindustry/dams/

What is Biomass energy?

• Energy from once living things• It is energy derived from burning organic material

such as wood, alcohol (ethanol), and garbage.

http://www.energyquest.ca.gov/story/chapter10_flash/index.html

•negative– pollutes, damages habitats, contributes to global warming

•Positive - renewable

XIV. What is geothermal energy?

• It is energy obtained by using hot magma or hot, dry rocks inside of the earth.

• Water is piped into the earth and becomes steam when it is heated by rocks or magma. The steam turns turbines that run the generator to make electricity.

• positives: renewable, no pollution, does not contribute to global warming

• negatives: Expensive to install