M A PM A P ssMeaningful Applications of Physical ScienceDr. M. H. Suckley & Mr. P. A. KlozikEmail: MAP@ScienceScene.com

Welcome

A. Nature of Heat

B. Expansion and Contraction

C. Heat Transfer

D. Change of State (Latent Heat)

E. Relating Heat, Energy and YOU

Naïve Ideas

A. Nature of Heat

1. The Production of Heat and Other Forms of Energy a. Where Does Heat Energy Come From? . . . . . . . . . . . . . . . . . .11

b. Transformation of Chemical Energy to Heat Energy . . . . . . . . .11 2. Different Materials Absorb Heat Energy at Different Rates a. Colors and the Absorption of Heat Energy . . . . . . . . . . . . . . . 13 b. Different Materials and Their Absorption Of Heat Energy . . . . 15

3. Temperature and Heat a. Sensing Temperature – The Three Tubs . . . . . . . . . . . . . . . . . 23 b. How Is Temperature Different From Heat? . . . . . . . . . . . . . . . 20 c. What Happens to Temperature When Water Changes State . . 24

B. Expansion and Contraction 1. The Addition of Heat Energy Usually Causes Solids To Expand a. The Expanding Shower Curtain Rod . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 b. Ball and the Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 c. Bimetallic Strip and Linear Expansion and Contraction . . . . . . . . . . . . . . Demo

2. The Addition of Heat Energy Usually Causes Liquids to Expand a. How Can You Compare the Expansion of Liquids . . . . . . . . . . . . . . . . . .35 b. Hand Boilers and Lava Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 c. Liquids, Heat and Lake Turnover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Slide

3. The Addition of Heat Energy Usually Causes Gases To Expand a. Measuring the Expansion of Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 b. Crushing the Can (Ditto/Soda Cans). . . . . . . . . . . . . . . . . . . . . . . . . . . . . Demo c. Nerf Ball Cannons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Demo d. Egg in the Milk Bottle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Demo e. Hero’s Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Demo

4. Measuring Temperature Using the Principle Of Expansion a. Making and Calibrating A Thermometer. . . . . . . . . . . . . . . . . . . . . . . . 48

C. Heat Transfer 1. Heat Moves From Areas Of Higher Temperatures To Lower a. Placing A Metal Strip in Hot Water . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 b. Match and Fork and Copper Coil in Flame. . . . . . . . . . . . . . . . . . . . . 55

2. Temperature Equilibrium a. The Affect of Heated Objects On Their Surroundings . . . . . . . . . . . . . 57 b. The Law of Conservation of Heat Energy . . . . . . . . . . . . . . . . . . . . . . Slide

c. Mixing Water of Different Temperatures . . . . . . . . . . . . . . . . . . . . . . . 60

3. Conduction a. How Quickly Does Heat Energy Travel?. . . . . . . . . . . . . . . . . . . . . . . . . 67 b. Conducting Heat Energy through Metals . . . . . . . . . . . . . . . . . . . . . . . 71

4. Convection a. The Boiling Pot - Rheoscopic Fluid (Hot Plate & Beaker) . . . . . . . . . . . 76 b. Building a Heat Mobile . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 79 c. Why Does the Water Mix (Convection Currents). . . . . . . . . . . . . . . . . . 80

Why Does the Water Mix (Baby Food Jars) . . . . . . . . . . . . . . . . . . Demo Aquarium (Cold Water) and Bottle (Hot Water) . . . . . . . . . . . . . . . . Demo d. Movement of Air Through A Room . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

5. Radiation - Using Cans to Transfer Heat Energy . . . . . . . . . . . . .87

6. Insulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Slide

D. Change of State (Latent Heat)

1. Change of State and Temperature . . . . . . . . . . . . . . . . . . . . . 95

2. Evaporation and Temperature (3 Sprays) . . . . . . . . . . . . . . . . 98

3. Drinking Bird . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Demo

4. Boiling, Bubbles, And Temperature . . . . . . . . . . . . . . . . . . . . .121

5. Heat Packs and Latent Heat . . . . . . . . . . . . . . . . . . . . . . . . . . 106

6. Water Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110

E. Relating Heat, Energy and YOU . . . . . . . . . . . . . . .112

We Had A Great Time

Naive Ideas

1. Heat is a substance.

2. Temperature is a property of a particular material.

3. The temperature of an object depends on its size.

4. Heat and cold are different.

5. When heat is applied temperature always increases.

6. All solids expand at the same rate.

7. All liquids expand at the same rate.

8. All gases expand at the same rate.

9. Objects of different temperatures in contact with each other, do not move towards the same temperature.

10. Heat energy only travels upward (rises).

11. Objects which warm quickly do not cool quickly.

12. The temperature of Ice always remains constant.

13. The bubbles in boiling water contain "air", "oxygen", or "nothing”.

14. All liquids boil at 100°C (212°F) and freeze at 0°C (32°F).

14

Where Does Heat Energy Come From?

1. HEAT ENERGY FROM MECHANICAL ENERGY: Rubbing Hands Bending Metal (coat hanger) Hammering a Nail (hammer, nail, piece of wood) Shaking (2 Styrofoam cups, sand, strong tape, thermometer)

2. HEAT ENERGY FROM CHEMICAL ENERGY: Heat Pack Cold Pack Plaster of Paris

3. HEAT ENERGY FROM LIGHT ENERGY: Light Bulb Sun Light

21

Energy Conversions

ChemicalElectricalSoundHeatMechanicalLight

Cooking Food

ThermocoupleTeapotExpansionFireHeat

50

Transformation Of Chemical Energy To Heat Energy

Add water to Plaster of Paris, while constantly stirring, until syrupy.

1. Light a Match

2.

3. Heat energy stored in food:

a. obtain a piece of cardboard approx. 15-cm square and cover with aluminum foil.

b. insert a straight pin through the cardboard and aluminum foil.

c. place a peanut on the pin and light using a match.

OR

OR

2

Temperature

Temperature is a measure of the average kinetic energy associated with the

disordered microscopic motion of atoms and molecules. Temperature is not

directly proportional to internal energy since temperature measures only the

kinetic energy part of the internal energy, so two objects with the same

temperature do not in general have the same internal energy.

Temperatures are measured in one of the three standard temperature scales

(Celsius, Kelvin, and Fahrenheit).                                         

4

Heat

Heat may be defined as a form of energy existing as the result of the

random motion of the molecules and is in transit from a high temperature

object to a lower temperature object. The amount of this energy is

dependent upon the temperature change, mass of the material and the

heat storing capacity, specific heat, of the material.                             

Heat =

3

H = M x T x c

Mass x T(change in temperature) x c(Specific Heat)

4

Fahrenheit scale - Daniel Fahrenheit made a thermometer, stuck it in

freezing water and marked the level of the mercury on the glass as 32

degrees and then stuck the same thermometer in boiling water and marked

the level of the mercury as 212 degrees. The distance between those two

points were divided into 180 divisions.

Celsius scale - Anders Celsius arbitrarily decided that the freezing and

boiling points of water would be separated by 100 degrees. The boiling

point of water became 100 and the freezing point became 0 degrees.

Kelvin Scale - The International System of Measurements (SI) uses the

Kelvin scale for temperature.  The Kelvin scale is based on the concept of

absolute zero, the theoretical temperature at which molecules would have

zero kinetic energy.  Absolute zero, which is about -273.15 oC, is set at

zero on the Kelvin scale.  This means that there is no temperature lower

than zero Kelvin, so there are no negative numbers on the Kelvin scale.

Thermometers

2

.

  Comparison of Temperature Scales

Set Points Fahrenheit Celsius Kelvin

water boils 212 100 373

body temperature

98.6 37 310

water freezes 32 0 273

absolute zero -460 -273 0

Comparison of Thermometers

1

Sensing Temperature – The Three Tubs

0

IceWater

Room Temperature

HotWater

Get three bowls big enough to put your hands in. Fill one of them with very warm (but not boiling) water, and fill the second with cold water. Then pour equal amount s of hot and cold water into the third bowl.

Okay now, put one hand in the warm water and the other hand in the cold water for, say, a minute. Now one at a time put your hands in the in-between bowl of water.

The hand in hot water will sense cold and the hand in cold water will feel warmth. It’s hot and cold at the same time!

Thermal Properties of Selected Materials:

Substance

Specific HeatSpecific HeatThermal

Expansion:cm/cm oC

Thermal conductivity:

cal/sec cm oC Calories

cal/g oC Joules

J/g K

Aluminum 0.220 0.921 0.000026 0.4900

Brass 0.087 0.364 0.000019 0.2600

Copper 0.091 0.381 0.000017 0.9200

Glass 0.160 0.669 0.000009 0.0020

Iron 0.110 0.461 0.000011 0.2000

Steel 0.000011

Lead 0.030 0.126 0.000029 0.0830

Water 1.000 4.187 0.001430 0.0014

Ice 0.500 2.094 0.001326 0.0040

Wood 0.420 1.759 0.000400 0.0002

Sand 0.200 0.837 1

Color Absorption

0

Materials and Their Absorption of Heat Energy

Material Perceived Temperature (Place check) Actual Temperature °C

Foam Rubber __cold, __cool, __room temp., __warm, __hot

Sand __cold, __cool, __room temp., __warm, __hot

Glass Marbles __cold, __cool, __room temp., __warm, __hot

Steel Shot __cold, __cool, __room temp., __warm, __hot

Gravel __cold, __cool, __room temp., __warm, __hot

Wool Fabric __cold, __cool, __room temp., __warm, __hot

Plastic Shot __cold, __cool, __room temp., __warm, __hot

Lead Shot __cold, __cool, __room temp., __warm, __hot

Lamb's Wool __cold, __cool, __room temp., __warm, __hot

Potting Soil __cold, __cool, __room temp., __warm, __hot

Observe materials and record perceived and actual temperatures

Water Cycle

Expansion of SolidsThe Expanding Shower Curtain Rod

Figure 1

Figure 2Figure 3

Curtain Rod

Block of Wood

PVC Pipe

Laser

Pin/wire

Mirror

Wooden Dowel

Ball and Ring

The ball easily passes through the ring at room temperature.

After heating the ball it no longer pass through the ring.

Expansion of Liquids

Hand Boilers and Lava Lamp

1

Hand Boilers Lava Lamp

ConductionConduction is the transfer of energy through matter

from particle to particle. It is the transfer and

distribution of heat energy from atom to atom within a

substance. For example, a spoon in a cup of hot soup

becomes warmer because the heat from the soup is

conducted along the spoon.

Conduction is most effective in solids-but it can

happen in fluids. Fun fact: Have you ever noticed that

metals tend to feel cold? Believe it or not, they are

not colder! They only feel colder because they

conduct heat away from your hand. You perceive the

heat that is leaving your hand as cold.

1

Heat Conduction

         

Heat moves from higher temperature to lower temperature             

                                        T2                                              T1                   

                                           

0

Convection

                       

Hot water rises, cools,and falls.

                           

Heated air rises, cools, thenfalls.  Air near heater isreplaced by cooler air, and the cycle repeats.

                        What if coils were at the bottom?

Convection is the transfer of heat by the movement of the warmed matter. Convection is the transfer of heat energy in a gas or liquid by movement of currents. The heat moves with the fluid.

4

Convection Currents

This picture shows a gas burner and its

shadow on a screen. The flame gives

rise to a plume of hot gases that rise

above the burner. This disturbs the air

and casts a shadow, which reveals how

the moving air carries away the energy of

the flame: an example of energy transfer

by convection

3

   Natural Convection

                          

Air above warmer groundrises.

                           

An Inversion layer is a laver of air near the ground that is more dense than air higher up; no convectioncurrents to lift pollutants.

                   

In a forest fire very hot, low-density air is buoyed upward,carrying thermalenergy with it.

2

Sea Breezes

1

Urban Heat Islands

Cities are hotter than surrounding country because:

1. Re-radiation from concrete, asphalt, etc.

2. Industrial & human activity.

3. Quick overland flow eliminates evaporative cooling.  

0

Heat Mobile

1

Why Does the Water Mix?

1. Fill one jar to the top with hot water. (It must be filled to the very top).

2. Fill the other Jar with cold water and add several drops of food coloring to it.

3. Put the index card on top of the hot water jar, hold the card in place, and turn the jar upside down, placing it on top of the cold water jar.

4. Slide the card out slowly and watch what happens.

8

Radiation

Energy is used to broil a fish. The red glow on the

heating element is the visible part of the light energy,

but there is far more invisible infrared light being emitted.

Energy is transferred as electromagnetic energy from the

heating element to the fish: an example of transfer of

energy by radiation.

HEAT RADIATION is electromagnetic waves that directly

transport energy through space. Sunlight is a form of

radiation that is radiated through space to our planet at the

speed of light without the aid of fluids or solids. The energy

travels through nothingness! Thus, radiation brings heat to

our planet.

3

Heat Radiation Due to Color

2

Fill each can with equal amounts of hot water. Place a lid with a thermometer inserted on each can.

MEASURE the initial temperature in each can. RECORD the temperatures in the table.

Heat Radiation Due to Color

55.248.046.065

57.049.547.260

58.551.549.055

61.254.051.050

62.055.253.045

63.857.054.540

66.059.557.035

68.062.559.530

71.065.562.525

73.569.266.020

76.873.070.015

80.077.074.010

84.083.080.55

93.093.093.00

Silver CanWhite CanBlack CanTime

1

14

Graph - Heat Radiation Due to Color

35.0

45.0

55.0

65.0

75.0

85.0

95.0

0 5 10 15 20 25 30 35 40 45 50 55 60 65

Black

Silver

White

0

Insulators

                                  

Ice upon freezing gives up heat toplants.  Ice also has a low thermalconductivity.

                         

 Ice on cooling coils will slow the removal of thermal energy from the air.

The principle behind a bimetallic strip thermometer relies on

the fact that different metals expand at different rates as they

warm up. By bonding two different metals together, you can

make a simple electric controller that can withstand fairly high

temperatures. This sort of controller is often found in ovens.

Bimetallic Strip

1

How Can You Explain The Sagging Telephone Line?

Winter Summer

10

Fahrenheit scale - Daniel Fahrenheit made a thermometer, stuck it in

freezing water and marked the level of the mercury on the glass as 32

degrees and then stuck the same thermometer in boiling water and marked

the level of the mercury as 212 degrees. The distance between those two

points were divided into 180 divisions.

Celsius scale - Anders Celsius arbitrarily decided that the freezing and

boiling points of water would be separated by 100 degrees. The boiling

point of water became 100 and the freezing point became 0 degrees.

Kelvin Scale - The International System of Measurements (SI) uses the

Kelvin scale for temperature.  The Kelvin scale is based on the concept of

absolute zero, the theoretical temperature at which molecules would have

zero kinetic energy.  Absolute zero, which is about -273.15 oC, is set at

zero on the Kelvin scale.  This means that there is no temperature lower

than zero Kelvin, so there are no negative numbers on the Kelvin scale.

Thermometers

1

.

  Comparison of Temperature Scales

Set Points Fahrenheit Celsius Kelvin

water boils 212 100 373

body temperature

98.6 37 310

water freezes 32 0 273

absolute zero -460 -273 0

Comparison of Thermometers

0

How Is Temperature Different From Heat?

1. Place the two bolts into a beaker of water. Heat the water until it bolls for several minutes. Are the bolts at the same temperature?

2. What is the temperature of the bolts?3. Use the tongs to remove the large bolt from the hot water. 4. Read temperature of hot water and immediately put it in one of the

cups of tap water. 5. MEASURE and RECORD any changes in the water temperature for

a period of three minutes.

Initial Temperature

1 Min. 2 Min 3 Min.

Spring: Surface ice (0°C) melts and becomes denser when it warms to 4°C, and then

sinks. This sinking, along with spring winds, causes mixing of water until all

the water becomes 4°C. This is Spring Turnover, which results in mixing the

O2 rich upper waters with nutrient-rich lower waters.

Autumn: Time of fall turnover. The surface cools and becomes denser and sinks.

Again, nutrient- and oxygen-rich waters will mix, and the "fall bloom" will

occur.

Lake Turnover

Measuring The Expansion Of Air

What Happens When Water Changes State

Latent Heat

100 0 -30

melting

Boiling

Calories per gram needed for change in State

solid

Liquid

Gas

80 cal/gr

540 cal/gr.

Temp.

0 5 10 15 20 25 30 35 40 45 Time

1 cal/gr. for each degree

Time - min Temp. - 0C

0

5

10

15

20

25

30

35

40

45

1

What Happens When Water Changes State

Latent Heat

100 0 -30

melting

Boiling

Calories per gram needed for change in State

solid

Liquid

Gas

80 cal/gr

540 cal/gr.

Temp.

0 5 10 15 20 25 30 35 40 45 Time

1 cal/gr. for each degree

0

Change of State and Temperature Latent Heat

Latent Heat

100 0 -30

melting

Boiling

Calories per gram needed for change in State

solid

Liquid

Gas

Temp.

0 5 10 15 20 25 30 35 40 45 Time

Boiling540 cal/gram

Heating1 cal/gram per

degree

Melting80 cal/gram

Drinking Bird

When water evaporates from the fuzz on the Dippy Bird's head, the head is cooled. The temperature decrease in the head condenses the methylene chloride vapor, decreasing the vapor pressure in the head relative to the vapor pressure in the abdomen.

The greater vapor pressure in the abdomen forces fluid up through the neck and into the head. As fluid enters the head, it makes the Dippy Bird top-heavy.

The bird tips. Liquid travels to the head. The bottom of the tube is no longer submerged in liquid.

Vapor bubbles travel through the tube and into the head.

Liquid drains from the head, displaced by the bubbles. Fluid drains back into the abdomen, making the bird bottom-heavy.

The bird tips back up

The Heat Pack and Latent Heat

The heat pack contains a solution of sodium acetate tri-hydrate in water. This solution has a very large heat of crystallization, which means it gives out a significant amount of energy on solidifying or crystallizing. (temperature rise to around 50 °C). This ability to store heat energy in is referred to as latent heat.

1

               Does Heat Loss Equal Heat Gain?

0.4    1.27 5.13Percent of Error

450247895733Theoretical Value

44844728   6027Heat loss: (c)Hhot = MH20,hot x Thot x c

45204850     5439Heat gain: (c)Hcold = MH20,cold x Tcold x c

20-°C 50-°C   37-°C Tcold (oC)

59-°C 24-°C 41-°C   Thot (oC)

24-°C 51-°C 40-°C  TFinal (oC)

4-°C 1-°C 3-°C  Tcold (oC)

82-°C 75-°C 81-°C  Thot (oC)

 76-g197-g147-g    MH20,hot (g)

79-g200-g150-gMH20,hot-water + Cup (g)

3-g3-g3-gMhot-water Cup (g)

225-g  97-g   147-g   MH20,cold (g)

 228-g    100-g150-g   MH20,cold-water + Cup (g)

3-g3-g3-gMcold-water Cup (g)

Trial 3 75-g. hot +225-g. cold

Trial 2200-g. hot + 100-g. cold

Trial 1150-g. hot + 150-g. coldData: Conservation of Energy

27

How Quickly Does Heat Energy Travel?

1. Take each metal and hold it for about 10 seconds. DESCRIBE how each material feels to your hand.

2. Carefully pour hot water into the Styrofoam cup. Place all the strips in the cup at the same time. Touch the ends of the strips to see which one gets warm first. List the ORDER in which the materials get warm.

3. CLASSIFY each of these materials as good heat conductors, fair heat conductors, or poor heat conductors.

Copper

Aluminum

Iron

Plastic

Wood

Conducting Heat Energy through Metals

Lay the copper strip on the table. Make pencil lines at 2-cm intervals along the strip. Use a match to slightly melt the bottoms of the birthday candles and stick them on. Turn the strip over and place it upside down over the ring.Light the burner and place it under one end of the strip.

Light the candle and allow a small drop of wax to drip onto the end of each metal rod. While the wax is still liquid, attach a small strip of paper to each rod.Light the burner and place it under the center of the apparatus.MEASURE and RECORD the time that it takes for the paper strips to fall off the rod.

Placing A Metal Strip in Hot Water

Place the end of the straight strip of metal in the cup of hot water.

Wait about 15 seconds and then DESCRIBE what you feel when you touch the top of the strip.

Bend strip and repeat.

Match and Fork and Copper Coil in FlameKindling Point

Heated Objects Affect On Their Surroundings

Insert a thermometer in each rubber stopper.

Mount the stoppers in the holes in the cardboard.

Fill the test tube with hot water.

Place one stopper and thermometer in the test tube. Place the whole lid assembly over a Styrofoam cup.

MEASURE the initial temperatures of both the air and the water.

Continue measuring and recording the temperatures at one minutes intervals for six minutes.

Thermometer Placement

Temperature (Each Minute)

0 1 2 3 4 5 6

Hot Water

Air

Cup Size

Small

Medium

Large

The Law of Conservation of Energy

m x ∆T x c = m x ∆T x c 

Heat Lost = Heat Gained

2

Heat, Energy, And YOU!

Stair height

Height

TrialForce

F (newtons) Distance

d(meters) Work

W (joule) Calories

cal. = W / 4.19

1

2

3

Av.

We Had A Great Time