Energy Transformations 6.14.spi.3 The student is able to recognize a variety of energy transformations.

Energy TransformationsEnergy Transformations

6.14.spi.36.14.spi.3

The student is able to The student is able to recognize a variety of energy recognize a variety of energy

transformations.transformations.

Getting the IdeaGetting the IdeaENERGY is the ability to do work and ENERGY is the ability to do work and comes in many forms and from many comes in many forms and from many

sources.sources.

ENERGY comes from heat, ENERGY comes from heat, chemicals, electricity, gasoline, chemicals, electricity, gasoline,

and the food you eat.and the food you eat.ENERGY cannot be destroyed, ENERGY cannot be destroyed, but it can be changed from one but it can be changed from one

kind of energy to another.kind of energy to another.

Light energy can be Light energy can be changed into heat changed into heat energy.energy.

Electrical energy can Electrical energy can be changed into be changed into sound energy.sound energy.

The Law of Conservation of EnergyThe Law of Conservation of Energy

This law states that energy cannot be created of This law states that energy cannot be created of destroyed but can change from one type to destroyed but can change from one type to another.another.

Potential energy can be changed into kinetic Potential energy can be changed into kinetic energy. Every time one type of energy changes energy. Every time one type of energy changes into another type, no energy is lost. The same into another type, no energy is lost. The same amount of energy is there at the end as was amount of energy is there at the end as was there at the beginning.there at the beginning.

It is just in a different form.It is just in a different form.

Potential and Kinetic Energy Potential and Kinetic Energy TransformationsTransformations

MECHANICAL ENERGY is the energy an MECHANICAL ENERGY is the energy an object has because of its motion or object has because of its motion or position. position.

KINETIC ENERGY is energy of motion.KINETIC ENERGY is energy of motion.

POTENTIAL ENERGY is energy of POTENTIAL ENERGY is energy of position.position.

Potential energyPotential energy

It is energy that an object It is energy that an object has stored and can use.has stored and can use.It can be changed into It can be changed into energy of motion if a energy of motion if a force is used to start the force is used to start the object moving.object moving.A watermelon resting on A watermelon resting on the roof of a building has the roof of a building has the ability to fall the ability to fall downward but will not downward but will not move until something move until something pushes it.pushes it.So it has potential energy So it has potential energy but no kinetic energy.but no kinetic energy.

As the watermelon is falling, its POTENTIAL As the watermelon is falling, its POTENTIAL ENERGY is being changed into energy of ENERGY is being changed into energy of motion, or KINETIC ENERGY. motion, or KINETIC ENERGY.

By the time it hits the ground, it is moving pretty By the time it hits the ground, it is moving pretty fast because all of its POTENTIAL ENERGY fast because all of its POTENTIAL ENERGY has been changed into KINETIC ENERGY.has been changed into KINETIC ENERGY.

Right before it hits the ground, it has as much Right before it hits the ground, it has as much KINETIC ENERGY as it can have, and its KINETIC ENERGY as it can have, and its POTENTIAL ENERGY is zero, since it is at the POTENTIAL ENERGY is zero, since it is at the level of the ground and can’t fall farther.level of the ground and can’t fall farther.

In pieces on the ground, the watermelon In pieces on the ground, the watermelon has stopped moving.has stopped moving.

Now it has no POTENTIAL ENERGY Now it has no POTENTIAL ENERGY because it has nowhere farther to fall. because it has nowhere farther to fall.

It also has no KINETIC energy because it It also has no KINETIC energy because it isn’t moving anymore.isn’t moving anymore.

CHEMICAL ENERGY CHEMICAL ENERGY TRANSFORMATIONSTRANSFORMATIONS

When you turn on a flashlight, an energy When you turn on a flashlight, an energy transformation occurs.transformation occurs.

CHEMICAL ENERGY IS THE ENERGY CHEMICAL ENERGY IS THE ENERGY STORED IN THE BONDS THAT HOLD STORED IN THE BONDS THAT HOLD

CHEMICAL COMPOUNDS CHEMICAL COMPOUNDS TOGETHER.TOGETHER.

Batteries contain chemical energy that can be Batteries contain chemical energy that can be used to do work if they are connected in a used to do work if they are connected in a circuit.circuit.

When you turn the flashlight on, the batteries’ When you turn the flashlight on, the batteries’ chemical energy is turned into electrical energy chemical energy is turned into electrical energy that moves through the flashlight wires.that moves through the flashlight wires.

When the electrical energy reaches the When the electrical energy reaches the lightbulb, it is changed into light energy. lightbulb, it is changed into light energy.

Since the lightbulb gets hot, some of that Since the lightbulb gets hot, some of that electrical energy is also changed into heat electrical energy is also changed into heat energy. energy.

Energy was not created or lost.Energy was not created or lost.

All it did was change form, from chemical All it did was change form, from chemical energy into electrical energy into light and energy into electrical energy into light and heat energy.heat energy.

ELECTRICAL ENERGY ELECTRICAL ENERGY TRANSFORMATIONSTRANSFORMATIONS

Your alarm goes off in the morning.Your alarm goes off in the morning.

You turn the light on next to your bed.You turn the light on next to your bed.

At breakfast, your toast pops up out of the At breakfast, your toast pops up out of the toaster, ready to eat.toaster, ready to eat.

All day long, electrical energy is moving All day long, electrical energy is moving and changing into other forms of useful and changing into other forms of useful energy.energy.

ELECTRICAL ENERGY is energy ELECTRICAL ENERGY is energy produced by moving electric charges.produced by moving electric charges.

Think about your alarm clock.Think about your alarm clock.

It is plugged into the wall.It is plugged into the wall.

At a set time in the morning, it At a set time in the morning, it makes a loud noise.makes a loud noise.

To do this, ELECTRONS To do this, ELECTRONS FLOW OUT OF WALL FLOW OUT OF WALL SOCKET, MOVE THROUGH SOCKET, MOVE THROUGH WIRED THROUGH THE WIRED THROUGH THE CLOCK.CLOCK.

Electrons give off their energy Electrons give off their energy to the part of the clock that to the part of the clock that makes the sound.makes the sound.

This part changes electrical energy into This part changes electrical energy into sound energy. sound energy.

That SOUND ENERGY travels in waves That SOUND ENERGY travels in waves through the air and into your eardrum.through the air and into your eardrum.

Good morning!Good morning!

Now, you follow electrical energy through Now, you follow electrical energy through a lamp.a lamp.

It ends as LIGHT ENERGY. Some energy It ends as LIGHT ENERGY. Some energy is wasted as it is changed into HEAT is wasted as it is changed into HEAT ENERGY and makes the light bulb HOT.ENERGY and makes the light bulb HOT.

SOLAR ENERGYSOLAR ENERGY

It comes from sunlight.It comes from sunlight.

It can be transformed into It can be transformed into electrical energy.electrical energy.

Electromagnetic energy Electromagnetic energy from sunlight is converted from sunlight is converted into electric energy to heat into electric energy to heat and cool homes and run and cool homes and run appliances.appliances.

DISCUSSION QUESTIONDISCUSSION QUESTION

Can you think of examples from your life of Can you think of examples from your life of the following energy transformations?the following energy transformations?

A. electrical energy changed into heat A. electrical energy changed into heat energyenergy

B. potential energy changed into kinetic B. potential energy changed into kinetic energyenergy

C. chemical energy changed into light C. chemical energy changed into light energyenergy

Lesson ReviewLesson Review

1. Which energy change happens inside a 1. Which energy change happens inside a lamp?lamp?

A. Electrical energy turns into chemical A. Electrical energy turns into chemical energy.energy.

B. Light energy turns into electrical energy.B. Light energy turns into electrical energy.

C. Electrical energy turns into nuclear C. Electrical energy turns into nuclear energy.energy.

D. Electrical energy turns into light energy.D. Electrical energy turns into light energy.

2. You climb to the top of a hill to take a look at 2. You climb to the top of a hill to take a look at the view. Which energy transformation occurred the view. Which energy transformation occurred during your climb?during your climb?

A. potential energy turned into kinetic energy A. potential energy turned into kinetic energy

B. potential energy turned into chemical B. potential energy turned into chemical energyenergy

C. kinetic energy turned into potential energyC. kinetic energy turned into potential energy

D. kinetic energy turned into light energyD. kinetic energy turned into light energy

3. What cannot happen, according to the 3. What cannot happen, according to the law of conservation of energy?law of conservation of energy?

A. Energy can change form.A. Energy can change form.

B. Energy can be destroyed.B. Energy can be destroyed.

C. Energy can be changed from chemical C. Energy can be changed from chemical to heat.to heat.

D. Energy can be useful.D. Energy can be useful.

4. Which kind of energy does a battery 4. Which kind of energy does a battery have?have?

A. chemicalA. chemical

B. potentialB. potential

C. kineticC. kinetic

D. electricalD. electrical