By: Mrs. Crisp

Heat

S.P.I

0507.10.1Use data from an investigation to

determine the method by which heat energy is transferred from one object

or material to another.

Academic Vocabulary 

HeatThermal energy that flows between objects due to a

difference in temperature 

TemperatureA measurement of the average energy of particles in an

object

Thermal ConductivityThe ability of a material to transfer heat

 Conduction

The passing of heat through a material while the material itself stays in place

Academic Vocabulary 

ConvectionThe flow of heat through a liquid or gas, caused by hot parts

rising and cooler parts sinking 

RadiationThe transfer of heat through electromagnetic rays

What is heat?Have you ever taken a sip of a hot drink

and burnt your tongue?

OUCH!

Energy in the drink flows into your tissues and damages them. That energy that

causes the burn is heat.

What is heat?

Can you name some elements?

HeatThermal energy that flows between objects due to

a difference in temperature

Heat is measure in joules (J).

The reason the drink burned your tongue is because your tongue is cooler than drink so the heat flows from

the drink to your tongue.

What is heat?

Can you name some elements?

Heat moves from an object with a high temperature to an object with a lower temperature.

BUT…

WHAT IS TEMPERATURE?

TemperatureA measurement of the average kinetic energy of

particles moving in an object

What is heat?

Can you name some elements?

All the particles in an object are vibrating with kinetic energy. Objects with a higher temperature have

particles that are vibrating faster. Objects with a lower temperature have particles that do not vibrate as

much.

When a hot object touches a cold object, the particles in each object bump into each other. During the

collision, the particles from the hot object pass on some of their energy to the particles in the cold object.

The cold object is now warmer, and the hot object is not cooler.

What is heat?

Can you name some elements?

When heat moves from one object to another, both object’s temperatures change.

Heat will continue to change until both objects have the same temperature.

We measure temperature by using a thermometer.

When a thermometer touches an object, heat will flow either into or out of the thermometer. Then the

thermometer and the object are the same temperature, heat will stop flowing.

REMEMBER

TEMPERATURE AND HEAT ARE NOT THE SAME THING!

Temperature measures the average kinetic energy in an object.

Heat is the total amount of thermal energy an object releases.

Have you ever stirred a hot cocoa with a spoon and you notice the spoon is getting hot? The cocoa warmed the spoon and the spoon is

warming your fingers!

How did the heat get from the cocoa, to the spoon, to your fingers?

Have you ever…

How does heat travel?Conduction

The passing of heat through a material while the material itself stays in place.

As hot and cool parts of the liquid move, they cause rotating currents.

These currents spread thermal energy throughout the material.

ConvectionThe flow of thermal energy though a liquid or gas, caused by hot parts rising and cool parts sinking.

How does heat travel?

Convection causes many of the weather patterns of Earth.

In conduction, heat transfers directly from the stove top to

the pan to the eggs.

In convection, hotter water rises and colder water falls.

How does heat travel?

These waves include visible light, X rays, and radio waves.

Electromagnetic waves can travel through empty space. Matter is not needed for

radiation.

Earth’s surface is warmed by radiation from the sun.

RadiationThe transfer of energy through electromagnetic

waves

Infrared Rays

The electromagnetic rays they produce are called infrared rays.

Hot objects radiate heat.

What is thermal conductivity?

A good thermal conduction will conduct heat easily.

If a material conducts heat poorly, we say it is a thermal insulator.

When heat travels, it does not always travel at the same speed.

Thermal ConductivityThe ability of a material to transfer heat

Heat Capacity

Every substance has a unique heat capacity.

Materials with a low heat capacity change temperature quickly.

Water has a high heat capacity. This is why drinking cold water cools you down.

Can heat be a waste?

YES!

Can heat be a waste?

We need heat for lot of thing. We use heat to keep us warm. Chemical reactions require heat. There are just

a couple of example of why we need heat.

However, heat can also be a waste. Over time, heat from friction can cause machines to break. Friction

(heat) also lowers the efficiency of machines.

When energy changes forms or performs work, it will often produce waste heat.

QUESTIONS?