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In this blog your will find educational content related to heat and temperature taken from 8 class
LESSON PLAN FOR THE CHAPTER
Objectives
Students will be able to define heat and temperature
They will be able to describe heat loss and heat gain
Students will be able design the temperature and thermometer
Students will be able to Kelvin or absolute scale
Duration
The class duration is 45 minutes.
INTRODUCTION (10 minutes)
Begin the class with the introduction of heat and temperature
Also define heat and temperature to the students.
Recall the previous lesson to make connection between the lessons.
BODY ( 25 minutes )
The heat and temperature will be explained with detail and also practical examples will be given to the students to link them with real world knowledge.
Presentation
Using the visual aids like projector to present and show the videos of the heat and temperature in which have happened in different parts of the world
Discussion
Arranging a class discussion of the class to describe and highlights the impacts of natural disaster on human beings and environment.
CONCLUSION ( 10 minutes )
Summary
Summarizing the key points again to the students so they may get their doubts clear.
HOMEWORK
Give an assignment to the students to write down some examples of heat and temperature
HEAT AND TEMPERATURE
Heat is a form of energy. It travels from hot object to cold object. As we have learnt that particles in lall the three states of matter are always in a state of motion. The energy due to the motion of particles is called kinetic energy. It is also known as thermal energy. Heat is the measure of thermal energy of all the particles of a substance. We have also learnt that the tiny particles making all the three states of matter are atoms, molecules or ions, etc. Because of constant motion, the atoms and molecules in all the material objects have average kinetic energy. When an object is heated or cooled, the average kinetic energy of its atoms, molecules or ions increases or decreases (Figure 10.1
Heat loss or heat gain
When water or some other object is placed in a freezer, it loses thermal energy (heat loss). As a
result, it becomes cold. When some ice cubes taken in a beaker are heated on a burner, the thermal energy of ice increases (heat gain). As a result, it melts.
Temperature
When we touch a steel plate placed in the sunlight on a hot summer day, we feel that it is hot. When we touch the same plate placed outside in a winter night, we feel that it is cold. It is our sense of touch that tells us whether an object is hot or cold. The degree of hotness or coldness of an object is called its temperature. The hotter is an object, the greater is its temperature. Heat and temperature are closely related. The temperature of an object can be changed by the addition or removal of heat.
Thermometer
The device used to measure temperature of an object is called thermometer.A thermometer is usually made of a glass tube having a fine bore in it. The tube contains a bulb at its lower end. The bulb is filled with mercury or alcohol ( Figure 10.2). When the bulb of a thermometer is made in contact with the hot object, the alcohol/mercury expands and its level rises in the tube. At a cold place, the alcohol/mercury contracts and its level falls down in the tube. The alcohol or mercury level in the glass tube indicates the temperature.
Common Scales of Temperature
Short lines are marked on the thermometer to note the alcohol/mercury level. These are called temperature scales. Two temperature scales are commonly used:
(i) Centigrade or Celsius scale
(ii) Fahrenheit scale
Figure 10.3 shows the two scales on the
thermometers. These
scales are based on the temperatures of melting of ice and boiling
On the Centigrade scale, the interval between two fixed temperatures is divided into 100 equal divisions. Each division is
called a centigrade degree (°C). On the Fahrenheit scale, the interval between two fixed temperatures is divided into 180 equal divisions. Each division is called a Fahrenheit degree.
Kelvin or Absolute scale for measuring temperature is adopted by System International (SI). As reference points, the freezing point of water in Kelvin scale is 273 K and the boiling point of water is373 K. Interval between these two fixed points is divided into 100 equal intervals. Each interval on the scale is called one Kelvin and denoted by K.
• For converting the temperature given in °C to Kelvins, 273 is added to the given value.
Temperature in K = Temperature in °C + 273
• For converting the temperature given in Kelvins to °C, 273 is subtracted from the given value.
Temperature in °C = Temperature in K – 273
For further information watch the video
Some important mcqz about today topic
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