Why the boy takes his hand away from the kettle? Why the boy takes his hand away from the kettle?...

Why the boy takes Why the boy takes his hand away his hand away from the kettle?from the kettle?

Why the boy feels Why the boy feels the heat of the the heat of the kettle? kettle?

HEATHEAT

THERMAL EQUILIBRIUMTHERMAL EQUILIBRIUM

LEARNING LEARNING OBJECTIVESOBJECTIVES

Relationship between Relationship between temperature and heattemperature and heat

1.1. Temperature Temperature Temperature is a measure of the Temperature is a measure of the

degree of hotness of a body/ an degree of hotness of a body/ an object.object.

A hot body has high A hot body has high temperature, whereas a cold temperature, whereas a cold body has lower temperature.body has lower temperature.

2.2. Heat Heat Heat is a form of energy being Heat is a form of energy being

transferred from a hot body to a cold transferred from a hot body to a cold body.body.

Total amount of heat in a body depends Total amount of heat in a body depends on the mass, material and temperature of on the mass, material and temperature of the body.the body.

Heat and temperature are 2 different Heat and temperature are 2 different physical quantities. physical quantities.

TemperatureTemperature Heat Heat

The degree of The degree of hotness of a hotness of a body body

A form of A form of energy energy being being transferred transferred from a hot from a hot body to a body to a cold body.cold body.

Base quantity Base quantity unit : Kelvin (K)unit : Kelvin (K)

Measured in Measured in degrees Celsius degrees Celsius ((00C)C)

Derived Derived quantity unit: quantity unit: Joule (J)Joule (J)

Can be Can be measured measured using a using a thermometerthermometer

No specific No specific measuring measuring equipment.equipment.

Thermal EquilibriumThermal Equilibrium

Two object are in Two object are in thermal contactthermal contact when heat energy can be transferred when heat energy can be transferred between them.between them.

When two object with different When two object with different degrees of hotness come into degrees of hotness come into thermal contact, heat energy is thermal contact, heat energy is transferred between the two objects.transferred between the two objects.

Thermal equilibrium can be summarized as:Thermal equilibrium can be summarized as:There is There is no net flowno net flow of heat between two of heat between two objects that are in thermal equilibrium. Two objects that are in thermal equilibrium. Two object in object in thermal equilibriumthermal equilibrium have the have the same same temperaturetemperature. .

Thermal equilibrium does not depend on the:Thermal equilibrium does not depend on the:

i.i. Mass Mass ii.ii. Types of materialTypes of materialiii.iii. Size Size iv.iv. Shape Shape

Of the two object

The following are some examples of The following are some examples of objects in thermal equilibrium.objects in thermal equilibrium.

Liquid –in – glass Liquid –in – glass ThermometerThermometer

The liquid- in – glass Thermometer works on the The liquid- in – glass Thermometer works on the principle that liquids expands as the temperature principle that liquids expands as the temperature rises. rises.

The liquid used in thermometer must have the The liquid used in thermometer must have the following characteristics:following characteristics:A) Easily visibleA) Easily visibleB) Expands or contracts rapidly over a wide range B) Expands or contracts rapidly over a wide range of temperatureof temperatureC) Does not stick to the inside of the capillary tubeC) Does not stick to the inside of the capillary tube

The most commonly used liquids in the construction The most commonly used liquids in the construction of a liquid-in-glass thermometer are of a liquid-in-glass thermometer are MERCURYMERCURY and and COLOURED ALCOHOLCOLOURED ALCOHOL..

How thermometer How thermometer calibrate?calibrate?

EXERCISE 1EXERCISE 1

EXERCISES 2EXERCISES 2

EXERCISES 3EXERCISES 3