WEEK/TERM: THIRD TERM/WEEK 4
CLASS: J.S.S 1
TOPIC: THE CONCEPT OF TEMPERATURE AND HEAT
REFERENCE: ESSENTIAL PHYSICS FOR SENIOR SECONDARY SCHOOL
BRIEF EXPLANATION: Heat is a concept of physics that deals with the study of relative motion of fluid from one body to another. Temperature is sometimes mistakenly used to mean heat. Heat and temperature have different meanings entirely.
Heat measures the change in total internal energy or quantity of matter in a body while temperature is the degree of hotness and coldness of a body.
Notes for students (lesson one)
Heat is a form of energy due to a difference in temperature. Heat energy is a form of energy that flows from a substance at a higher temperature to the substance at a lower temperature thereby raising the temperature of the later and lowering that of the former substance provided that the volume remains constant.
Heat is measured in JOULES(J) and it is named after James Prescott Joules (1819-1889).
Temperature is the degree of hotness and coldness of a body. The units of measurement of temperature are Fahrenheit, Celsius, kelvin and Rankine. A thermometer is an instrument used in measuring temperature.
Qualities of a thermometer
Types of thermometer
- Constant volume gas thermometer
- Liquid in glass thermometer
- Resistance thermometer
- Radiation thermometer
- Thermo-electric thermometer (pyrometer)
Celsius scale = 0 – 100o
Kelvin scale = 273k – 373k
Fahrenheit = 32
Differences between heat and temperature
|It is a measure of the quantity of matter in a body
|It is the measure of hotness or coldness
|It is a derived quantity
|A fundamental quantity
|Not determined directly by an instrument
|Determined directly by a thermometer
|Measured in joules
|Measures in o Celsius, Fahrenheit
|It takes place due to temperature difference
|It occurs due to slight change in the state of a substance
EFFECTS OF HEAT
When heat is applied to a body, there would be changes in the physical properties of the body. These changes are:
- Temperature changes (rise in temperature)
- Change of state
- Contraction of the body
- Chemical changes
- Thermionic emission
- Change in pressure of the body.
Exercises / Assignment
- What is heat?
- State five effects of heat on substance (SSCE1990)
- Write in a tabular form, three differences between heat and temperature.
- List 4 types of thermometer.
- Write 2 qualities every thermometer must possess.
- Why is water not used as a thermometric substance? (SSCE 1991)