HEATEffect of HeatTemperature

Thermometer and its typesTemperature Scale and Conversion

Heat Transfer

How heat related to thermal energy?

• Any object is said to possess thermal energy due to the movement of its particles.

HEAT – is a form of energy that refers to the thermal energy that is “in transit” or in the process of being transferred.

EFFECT OF HEAT• When we heat a substance, the

movement of its molecules increases. This increases the average distance between the molecules. The heat causes expansion.

1. Expansion of Solid2. Expansion of Liquid3. Expansion of Gas

TEMPERATURE• It indicates the degree of

hotness or coldness of a body or a place.

• It is the quantity that tells how warm or cold an object is with respect to some standards.

THERMOMETER-is the device used to measure the

temperature.TYPES:1. MERCURY THERMOMETER- measure liquid

temperature.

2. ALCOHOL THERMOMETER – measure only up to 78’c.

3. CLINICAL THERMOMETER – measure body temperature.

4. LABORATORY THERMOMETER – can measure from -10’c to 110’c.

TEMPERATURE SCALE

• The amount of heat transferred is proportional to the temperature change.

1. CELSIUS SCALE (°C) – by Andres Celsius2. FAHRENHEIT SCALE (°F) – by Gabriel

Fahrenheit3. KELVIN SCALE (K) - by William

Thomson Lord Kelvin

HEAT TRANSFER1.CONDUCTION – takes place between objects that are in contact with each other.- Occurs in solids- Transfers heat from warmer part of the object to the cooler part.

HEAT TRANSFER1.CONDUCTION

Material Conductivity (K)AgCuAuAlIce

GlassConcrete

Water at 20°CRubberWood

429 401318237

21.71.10.6

0.160.04 – 0.4

HEAT TRANSFER2 CONVECTION– Occurs in fluids (Liquids and Gas)- Transfer of heat through the movement of particles.Warm particles rise, cool particles fill in space below.

HEAT TRANSFER3. RADIATION– Transfer of energy from the sun- Takes place even in the absence

of material.- All objects emit and absorb

radiation although some objects are better at emitting or absorbing radiation than others.

YES OR NO?1. Any object is said to possess thermal energy.2. The sun transfers energy to earth mainly by

radiation.3. The energy is distributed over the earth

primarily by conduction.4. The mother is able to hold the handle of the

pan with her bare hands when she making a soup because the handle is made of good insulator and has low thermal conductivity.

5. Object A has a higher temperature than object B. when they are in contact, the heat flows from A to B. this shows that A has greater heat than B.