Heat & Energy Heat & Energy Transfer Transfer Reassessment Reassessment ReviewReview

Directions

To start click “Slide Show” and “From Beginning”

As you go through the PowerPoint, take DETAILED notes on –

Each Energy FormEnergy ConversionsDirection of HeatWays Heat Travel

Nature of Energy

Energy is all around you!You can hear energy as sound.You can see energy as light.And you can feel it as wind.

Nature of Energy

You use energy when you: hit a softball. lift your book

bag. compress a

spring.

Nature of Energy

Living organisms need energy for growth and

movement.

Nature of Energy

Energy can be defined as the ability to do work.

Work only occurs when something is using energy.

Forms of Energy

The main forms of energy are:HeatChemicalRadiantElectricalNuclearMechanicalSound

Sound Energy Sound is the movement of energy through substances

in longitudinal (compression/rarefaction) waves.

Sound is produced when a force causes an object or substance to vibrate — the energy is transferred through the substance in a wave. Typically, the energy in sound is far less than other forms of energy.

Mechanical Energy

When work is done to an object, it gains energy. The energy it gains is known as mechanical energy and is associated with the motion of something.

It is the total of all the stored (or potential) energy AND the kinetic (moving) energy.

Mechanical Energy Example

When you kick a football, you give mechanical energy to the football to make it move.

Mechanical Energy Example

When you throw a bowling ball, you give it energy.

When that bowling ball hits the pins, some of the energy is transferred to the pins (transfer of momentum).

Electrical Energy)

Power lines carry electromagnetic energy into your home in the form of electricity. Electrical energy is the energy in the movement of electrons (those things buzzing around the nucleus of an atom).

Radiant Energy (Light)

Light is a form of electromagnetic energy that travels in rays through space.

Each color of light represents a different amount of radiant energy.

Electromagnetic Energy is also carried by X-rays, and laser light.

Heat Energy

The movement of atoms is called heat energy, because moving particles produce heat.

Heat energy can be produced by friction.

Heat energy causes changes in temperature and state of any form of matter (solid – liquid – gas).

WATCH THIS NOW!!!

Nuclear Energy

The nucleus of an atom is the source of nuclear energy.

Nuclear Energy - Fission When the nucleus splits (fission),

nuclear energy is released in the form of heat energy and light energy.

Nuclear Energy - Fusion

Nuclear energy is also released when nuclei collide at high speeds and join together (fusion).

Nuclear Energy

The sun’s energy is produced from a nuclear fusion reaction in which hydrogen nuclei fuse to form helium nuclei.

Nuclear Energy

Nuclear energy is we use comes from Uranium and is the most concentrated form of energy.

This energy is then used to heat water to make steam to spin a turbine that spins an electric generator.

Chemical Energy

Chemical Energy is required to bond atoms together.

And when bonds are broken, energy is released.

Remember the energy released in our Reaction In A Baggie Lab?

Chemical Energy

Fuel and food are forms of stored chemical energy. Food reacts with our bodies releasing energy and giving us the ability to move and function.

Energy Conversion

Energy can be changed from one form to another. Changes in the form of energy are called energy

conversions.

All forms of energy can be converted into other

forms.

Energy conversions

The sun’s light energy goes through solar panels and can be converted directly into electricity.

WATCH THIS!!!

Energy conversions

Green plants convert the sun’s light energy (electromagnetic) into starches and sugars (chemical energy).

Other energy conversions

In an electric motor, electromagnetic energy is converted to mechanical energy.

In a battery, chemical energy is converted into electromagnetic energy.

The mechanical energy of a waterfall is converted to electrical energy in a generator.

Energy Conversions

In an automobile engine: 1. the chemical energy in

fuel is burned to convert -

2. into heat energy. 3. The heat energy is then

changed -into mechanical energy to

move the car. (it also turns into sound energy right!?)

Chemical Heat Mechanical

The Law of Conservation of Energy

Energy can be neither created nor destroyed by ordinary means. It can only be converted from one form

to another. If energy seems to disappear, then

scientists look for it – leading to many important discoveries.

WATCH THIS!!!

Vocabulary Wordsenergymechanical energy

heat energychemical energyradiant energyelectrical energynuclear energyenergy conversionLaw of Conservation of Energy

Direction of Heat Transfer• Heat always moves from a warmer place to a cooler place.

• Hot objects in a cooler room will cool to room temperature as they give off heat energy.

• Cold objects in a warmer room will heat up to room temperature as they gain heat energy.

Heat always moves from hotter materials to the cooler materials.Your warm tea will give energy to the ice cubes until both the tea and the ice have reached the same temperature.

Direction of Heat Transfer

Heat travels in three ways, but how can we tell the difference?

Heat Transfers

EXAMPLE OF CONDUCTION

• A piece of cheese melts as heat is transferred from the meat to the cheese (Contact)

Examples of Convection:

Have you ever noticed that the air near the ceiling is warmer than the air near the floor? Or that water in a pool is cooler at the deep end?

Examples: air movement in a home, pot of heating water.

Examples of Radiation

1. Fire2. Heat Lamps3. Sun

Conduction Convection Radiation Song