+ T =

Hint:

It s the quantity of thermal energy given-off by a body

+ ature =

Hint:

The measure of the hotness or coldness of a body

+ + namics =

Hint:

A branch of physics

Prepared by:

MR. LAURO A. CALIVA

Heat and Temperature

• THERMAL ENERGY is the kinetic energy characterized by the randomness of motion at the atomic and molecular levels of a body.

• HEAT is the quantity of thermal energy absorbed or given-off by a body.

• TEMPERATURE is the measure of hotness or coldness of a body.

Heat and Temperature

• THERMODYNAMICS is a branch of physics concerned with the mechanical work, pressure, temperature and their roles in the transformation of energy.

Sources of Heat

• Natural Sources– The Sun– The Earth’s Interior

• Artificial Sources– Chemical Action– Electrical Energy– Mechanical Energy– Nuclear Energy

Measure of Heat

• THERMOMETER is any thermal sensor that measures temperature.

• The lines of a thermometer are called CALIBRATIONS.

• LIQUID-IN-GLASS THERMOMETER ROTARY THERMOMETER, THERMOCOUPLE THERMOMETER and LIQUID CRYSTAL THERMOMETER are a few examples.

1. LIQUID-IN-GLASS THERMOMETER

• Consists of a glass tube with a bulb on one end.

• The glass bulb contains a liquid (mercury or alcohol) that expands and narrows up.

2. ROTARY THERMOMETER

• Consists of coiled bimetallic strips.

• One strip is brass and the other is iron-made.

• The metals expand at different rates.

3. THERMOCOUPLE THERMOMETER

• An electronic thermometer.

• It operates under the principle of measuring changes in electric signal.

• It consists of two wires of different metals joined together at the ends to form junctions, and a display (to show the temperature).

3. LIQUID CRYSTAL THERMOMETER

• Consists of a strip of liquid crystals that changes color with temperature.

• Convenient to use but not very accurate.

TEMPERATURE SCALES

• In CELSIUS SCALE, the freezing point of water is 0 while the boiling point is 100 degrees Celsius.

• In FAHRENHEIT SCALE, the freezing point of water is 32 while the boiling point 212 degrees Fahrenheit.

TEMPERATURE SCALES

• In KELVIN SCALE, the freezing point of water is 273 K while the boiling point of water is 373 K.