TEMPERATURE

Standard CompentenceUnderstanding the scientific procedure to investigate the natural objects using equipments.

Basic CompetenceDescribing the meaning of temperature and its measurement.

C. Indicator to achieve Competence

Students are able to •Suggest why our senses can not be used to measure temperature.•Conduct an experiment using thermometer to measure the temperature change of an object.•Describe the characteristics of thermometer which is suitable to measure the temperature of a substance. •Inform the meaning of lower and upper fixed points in Celcius scale.•Inform the meaning of lower and upper fixed points in Fahrenheit scale.

• Inform the meaning of lower and upper fixed points in Kelvin scale.

• Conduct an experiment using unscale termometer to determine lower and upper fixed points.

• Converting the Celcius scale to Fahrenheit scale or vice versa.

• Converting the Celcius scale to Kelvin scale or vice versa

Temperature is one of the fundamental quantities. During the day we feel hot, but cool at night. Fire is hot, but ice is cold. A hot object is said to have high temperature, but a cold object has low temperature. Thus temperature shows the degree of hotness and coldness of an object. Your palm can feel the hotness or coldness of a thing. But can you use it to measure temperature?

How are temperature and Heat related ?1.

2. Why is the coils at the back of refrigerator feel hot ?

3. How do we measure temperature ?4. State the physical properties which varies with

temperature (Fill in the blank) ?

Physical properties Examples of Thermometer using Such properties

………………………………. Mercury-in-glass thermometer Alcohol-in-glass thermometer

………………………………… Thermocouple

………………………………… Resistance Thermometer

………………………………… Constant Volume gas Thermometer

There are 4 scales of thermometer 1.Celcius2.Reamur3.Fahrenheit 4.Kelvin

Kinds of thermometer

Celcius

Reamur Fahrenheit

Kelvin

The lower fixed point 0º 0º 32º 273º

The upper fixed point

100º 80º 212º 373º

Total of scale 100 80 180º 100

Freezing point (the lower fixed point) : is the temperature at which a liquid turns to ice.

Boiling point (the upper fixed point) : is the temperature at which a liquid changes to a gas.

The upper fixed point

The upper fixed point

Celcius Reamur Fahrenheit Kelvin

100º

80º

0º 0º

212º

32º

373º

273º

Celcius : Reamur : Fahrenheit : Kelvin

Boiling point of C : Boiling point of R : Boiling point of F : Boiling point of K

!00 : 80 : 212 : 373

Freezing point of C : Freezing point of R : Freezing point of F : Freezing point of K

0 : 0 : 32 : 273

Result 100 : 80 : 180 : 100

5 : 4 : 9 : 5

1. What is the SI Unit of Temperature? 2. Convert the following temperature ! a) 100ºC = ……ºR b) 20ºR = ……..ºC c) 40ºC = ……. ºF d) 60ºR = …….ºF 3. Convert the following temperature ! a) 68ºF = …….ºR= …….ºC=………ºK b) 303ºK = …….ºC= …….ºR= ……..ºF

Note

Lo = Length of mercury column for ice point (0ºC)

L100 = Length of mercury column for steam point (100ºC)

L = Length of mercury column for the unknown temperature (0ºC)

The 100ºC calibration mark of a mercury in glass thermometer is 30 cm

Above the bulb of the thermometer. The 0ºC calibration mark is 10 cm aboveThe bulb of thermometer.

What is the temperature when the mercury level is 25 cm above the bulb of

thermometer.

Known.

Question. Answer

= ?