This document discusses temperature, heat, and thermal equilibrium. It defines temperature as a measure of the average kinetic energy of atoms and molecules, while heat is the transfer of energy between objects due to a temperature difference. Thermal equilibrium is reached when the temperatures of two objects are equal and there is no net flow of heat between them. A liquid-in-glass thermometer, such as one using mercury or alcohol, measures temperature changes by the expansion of the liquid caused by a temperature change in the environment.

1. CHAPTER 4
Temperature, Heat &
Thermal Equilibrium

2. THINK IT OVER
HEAT = TEMPERATURE?
MORE HEAT = MORE TEMPERATURE?

3.  Heat - energy transfers from one object to
another because of temperature
difference
 Temperature - measure of the average
kinetic energy of the atoms
and molecules in substance

4. BRAIN POWER
Temperature Heat
Definition Measure of the
degree of hotness
A form of energy
Characteristic Determines the
direction of heat
flow
Transfer of energy from a
region of higher temp. to
another region of lower
temp.
Classification Base quantity Derived quantity
SI Unit Kelvin, K Joule, J
Other unit Celsius, oC Calorie, cal

5. Learning Outcomes
 At the end of the lesson, students
should be able to:
 1) explain thermal equilibrium
 2) explain how a liquid-in-glass
thermometer works.

6. How Does Thermal
Equilibrium Achieve?

7. Mechanism of Thermal Equilibrium
A
HOT
B
COLD +
Faster rate of
energy
transfer from
HOT to COLD
Slower rate
of energy
transfer from
COLD to HOT

8. HOT COLD

9. HOT COLD

10. Energy transferred at the same
rate between HOT and COLD
A B
No NET HEAT transfered

11. THERMAL EQUILIBRIUM :
Two object have same temperature
No net flow of heat between two objects
1
2

12. Liquid-in-glass thermometer
Mercury Alcohol
Freezing point : -39oC
Freezing point : -115oC
Boiling point : 357oC
Boiling point : 78oC
It does not wet the tube It wet the tube.
Opaque.
Easy to read.
Colorless.
It needs to be dyed.
Poisonous Safe liquid
Expensive Cheap
Conduct heat well,
responds faster to
temperature changes.
Responds more slowly
than mercury.

13. Liquid-in-glass
thermometer
 Calibration ( Penentukuran )

15. Mercury is used because :
 Opaque (Legap)
- easy to take reading
 Expands ( mengembang) uniformly with heat
- uniform scale
 High cohesive force ( daya lekitan tinggi )
- not stick to glass wall
 High Boiling point
- measure high temperature

16. Improve sensitivity
1. Narrow capillary tube
2. Thin glass wall bulb (bebuli)
3. Small bulb ( bebuli)

17. HOMEWORK
 Read about specific heat
capacity and write your own
notes.
 Ready for class after school
break.
 SELAMAT BerPHYSICS

18. Bye2