______________________________________Centre de Documentació i Experimentació en Ciències

TEMPERATURE AND HEAT Hot, cold, tepid or lukewarm. Write the corresponding English name in the chart below.

Fred Tebi Calent http://school.discoveryeducation.com/clipart/clip/brrrrrr.html

http://www.superstock.com/stock-photos-images/1538R-51155

Touch, feel, senses.

Sentits Tacte Sentir

http://bargasteacher.blogspot.com/2011/04/our-five-senses.html

http://www.northscottsdalewomenscare.com/bio_kschlecht.aspx

http://www.wefeelfine.org/

Higher, both, fill.

Tots dos Omplir Més alt

http://www.penkilnburn.com/paintings/21/

http://www.aiguesdebarcelona.cat/cat/servicio/facturas_tarifas/tarifas.asp

http://www.premiumpsd.com/3d-vector-onwards-upwards-arrows-psd-download.html

to allow permetre while mentre

Our senses allow us to feel if an object is cold or hot. The temperature of a hot object is higher than the temperature of a cold object. We can feel temperature through touch. Your notes:

THERMAL SENSATION (mini-practical activity) The brain’s conflict

Experiment: feeling the temperature. 1.-Fill a container with hot water, another one with cold water and a third one with lukewarm (tepid) water. 2.-Put one of your hands inside the hot water and the

other hand inside the cold water. 3.-A little while later, put both your hands in the lukewarm water container.

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http://so4j.com/what-is-a-lukewarm-christian.php

http://joysabroad.blogspot.com/2011/06/chinese-cure-all-is.html

http://purepro.com.ve/EC105.html

Questions:

YES/NO a) Do you feel the same sensation in both

hands? b) Do you think that touch allows us to know

the temperature of an object as accurately as a thermometer?

YES/NO

http://teleformacion.edu.aytolacoruna.es/FISICA/document/fisicaInteractiva/Calo er/T

What has happened? Why have you had different sensations when you have put your hands in lukewarm water? Let’s read the text in Catalan.

Explicació en Català: Quan posem en contacte dos cossos que tenen temperatures diferents, el que té més temperatura transmet energia al que en té menys fins que les temperatures dels dos cossos són iguals. L'energia es transmet entre dos objectes o cossos de forma espontània. És el que coneixem com a transmissió de la calor i sempre és des del cos que té la temperatura més elevada cap el què està més fred. Quan la temperatura dels dos objectes és la mateixa diem que s’ha produït l’equilibri tèrmic.El que el nostre cervell nota és la pèrdua o l’augment de calor. Believe it or not: el fred des del punt de vista de la Física no existeix!!!! A la pell tenim uns receptors que capten estímuls, un són sensibles (detecten) l’entrada de calor i uns altres detecten la sortida de calor. És per això que quan heu passat de l’aigua calenta a la tèbia el vostre cervell en processar la informació rebuda ha notat una disminució de temperatura. En canvi en passar de la freda a la tèbia ha notat un augment de temperatura. Així, la sensació que heu tingut a cada mà ha estat diferent.

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mperatura/Temperatura.htm

http://adamsapbio.wikispaces.com/Anatomy

TEMPERATURE AND MOLECULAR MOVEMENT

The temperature of an object depends on the kinetic energy (movement energy) of their particles. How will be the movement of the particles when the energy transfer has finished? The movement of the particles in both objects will be ___________ (the same/different) when the energy transfer finishes.

At the beginning In the end

http://www.physast.uga.edu/~rls/1020/ch4/ovhd.html

Cold object Hot object

We put two objects in contact, one is hot and the other is cold. The energy goes from the hot one to the cold one. In the end the particles of both objects will move at the same __________ (velocitat).

Here you have a drawing that represents the energy transfer from a hot object to a cold one. When does the energy transfer finish?

The transfer of energy finishes when both objects have the same temperature. The temperature of an object depends on the kinetic energy of the particles. When the particles move faster the temperature rises.

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http://www.geo4va.vt.edu/A3/A3.htm

http://www.physicsclassroom.com/class/thermalP/u18l1e.cfm

THE MEASUREMENT OF TEMPERATURE

Thermometers and scales to measure temperature

Temperature is measured with a thermometer. Thermometers based on the dilatation of liquids have inside mercury or alcohol. How do you think a thermometer based on the expansion of liquids work?

Scales to measure temperature Previous vocabulary What do these words mean: melt, boil, surface, freezing point, armpit, while?

Melt Boil Surface Armpit While Freezing point

• The Celsius or centigrade scale This scale is the one we use ourselves and know well. It is based on the changes of state of water. The point where ice melts has been assigned the value 0 degrees Celsius (0 ºC). The point where water boils at an atmospheric pressure of one atmosphere (1.013 hPa) is assigned a value of 100 degrees Celsius (100 ºC).

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http://www.physicscentral.com/experiment/physicsathome/bottle.cfm

Resum en Català: L’escala centígrada de temperatura o escala Celsius és…

• The Fahrenheit scale

This is used in Anglo-Saxon countries. In this scale ice melts at 32 ºF and water boils at 212 ºF. The equation to relate Fahrenheit to the Celsius scale is:. TF = TC 9/5 + 32 Tc= 5 (TF - 32)/9

L’escala Farenheit…

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• The Kelvin scale or absolute scale

Is used by scientists. In it the ice melts at 273 K and water boils at 373 K. The Kelvin is the unit of measurement of temperature of the International System. The equation to link it with the Celsius scale is: TK = TC + 273 Tc = TK – 273 L’escala Kelvin o escala absoluta…

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http://coolcosmos.ipac.caltech.edu/cosmic_classroom/light_lessons/thermal/measure.html

http://quimicadeisy.blogspot.com/2011/03/escala-de-temperatura-la-temperatura-es.html

a) Why, when we want to know if we have a fever do we

put the thermometer in the mouth, under the armpit or inside the rectum? Why do we need to wait a while to find out the temperature of our body? Answer in Catalan

Heat Heat is measured in Joules. Joules are the International System Heat unit. I am sure you have heard many times the concept calorie. This is not a International System unit, but is commonly used. A calorie is the heat you have to apply to raise the temperature of a gram of water by 1 ºC. Joule, an English physicist, calculated the equivalence with an experiment. This is the equivalence:

1.-What are Joules? 2.-What are calories? 3.-Which is the relationship between Joules and calories?

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1 calorie = 4,18 J (joules).

http://www.tokyofamilies.com/sections/entry.php?id=53

Transmission of Heat

There are three ways to transmit heat:

1. Conduction: Direct propagation of heat by contact between two objects. It is the transfer of energy through matter from particle to particle. 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.

2. Convection: Propagation of heat by the circulation of particles that occurs as a result of an object's body heat. This is the usual case with fluids where the substance to be heated drops its density and the particles rise to the highest point. When they arrive at the top they are cooled by the air in contact

with the surface and the density increases so the particles drop again. This produces the so-called convection currents.

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http://www.beodom.com/en/education/entries/principles-of-thermal-insulation-heat-transfer-via-conduction-convection-

http://yapshuqin789.blogspot.com/

http://whatscookingamerica.net/Appetizers/GrilledParmigianoSandwich.htm

Explain the movement of the particles in the convection currents created by the radiator.

3. Radiation: Propagation in the form of electromagnetic waves that travel through the atmosphere without heating anything until they reach an object which is opaque.

Electromagnetic waves directly transport ENERGY through space. Sunlight is a form of radiation that is radiated through space to our planet without the aid of fluids or solids. The energy travels through nothingness! Just think of it! The sun transfers heat through 93 million miles of space. Because there are no solids (like a huge spoon) touching the sun and our planet, conduction is not responsible for bringing heat to Earth. Since there are no fluids (like air and water) in space, convection is not responsible for transferring the heat. Thus, radiation brings heat to our planet.

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http://www.daviddarling.info/childrens_encyclopedia/heat_Chapter5.html

http://www.vtaide.com/png/heat2.htm

ONFORM PROPAGATI STATE EXAMPLE

CONDUCTION Direct contact between two Solids

objects

Liquids

The pot is heated by fireand the

heat is

act transmitted to the fluid inside by direct contwith it.

CONVECTION Circulation of particles Fluids

s heat p. This causes the

Tu

he liquids and gase

participles to circulate, going up and down.

RADIATION Through electromagnetic waves

Gas me towards you carrying energy and increasing the temperature of your hands.

When you put your hands in the pot you feel the waves of heat that co

http://faculty.icc.e i/prelab_i.htmldu/easc111lab/labs/lab

http://okfirst.mesonet.org/train/meteorology/HeatTransfer.html

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Let’s do some revision to see what we have learnt

efore beginning, have alook at the animations you will find here:

B http://www.wisc-online.com/Objects/ViewObject.aspx?ID=SCE304http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/energy/heatrev1.shtml

CONDUCTION: CONDUCTORS AND INSULATORS

.-Metals are good conductors of heat, in coad conductors of heat. What is the name usually used to indicate that a

onductor of heat?

.- We have a good understanding of what onvection is. Write down some convection rocesses that you know.

1.-What does it mean when we say that heat is transmitted by conduction? 2 ntrast wood and plastics are bmaterials is a bad c

CONVECTION 1cp

http://www.energyquest.ca.gov/story/chapter01.h tml

RADIATION 1.-Explain what happens in the drawings.

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Label all the thermal processes that are happening here.

AND KINETIC ENERGY

http://www.geo.arizona.edu/xtal/nats101/s04-08.html

TEMPERATURE

diminishes, cools, hotter, kinetic, increase

1.- The more ___________ energy that a body has, the faster its particles move. The particles move faster and collide with each other,

collisions produce an __________ in temperature. Therefore the object is ___________.

2.-When a body looses kinetic energy it ________, because the particles move less, and therefore there are fewer collisions between them. It is because of this that the temperature of the object _________________.

and these

http://www.cdxetextbook.com/engines/cool/fund/heattransfer.html

http://www.beodom.com/en/education/entries/principles-of-thermal-insulation-heat-transfer-via-conduction-convection-and-radiation

http://www.toaster-oven.net/deluxegrillingfryingpanplusafreemea

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ttenderizerworth995.aspx

Questions:

.-Why does temperature rise when a body is heated?

2.-Why temperature diminishes when a body loses heat?

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http://www.hk-phy.org/contextual/heat/cha/evapo02_e.html

http://www.google.es/imgres?q=kinetic+energy+ideal+gas&um=1&hl=es&rlz=1C1RNNN_enES369ES377&biw=1021&bih=634&tbm=isch&tbnid=6gVYSA2qb57R

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