Temperature and heat Thermal Equilibrium, Temperature Scales, Thermal Expansion, Quantity of Heat, Phase Changes, Mechanisms of Heat transfer
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Temperature and heat
Thermal Equilibrium, Temperature Scales, Thermal Expansion, Quantity of Heat, Phase
Changes, Mechanisms of Heat transfer
When a hot object warms a cooler object, does temp. flow between them? Are the temperature changes of the two objects equal?
Temperature and Thermal Equilibrium
• Temperature is a measure of hotness or coldness.• When an interaction causes no further change in
the system, then it is in the state of thermal equilibrium.
• Two systems are in thermal equilibrium if and only if they have the same temperature.
Thermometric Scales
Thermal Expansion
Linear expansion
Volume expansion
Linear expansion
https://dagnygromer.files.wordpress.com/2008/05/hyrail.jpg
https://littlekiwi83.files.wordpress.com/2012/08/dsc_0123.jpg
Volume expansion
http://www.kshitij-iitjee.com/Study/Physics/Part3/Chapter19/2.jpg
Quantity of Heat (Q)
Energy transfer that takes place solely because of temperature difference is called heat flow or
heat transfer, and energy transferred in this way is called heat.
Quantity of Heat (Q)
Calorie (cal) is defined as the amount of heat required to raise the temperature of one gram of
water from 14.5°C- 15.5°C
Conversion factors for the Quantity of Heat
1 cal = 4.186J1 kcal =1000 cal = 4186 J 1 Btu= 778 ft.lb = 252 cal = 1055 J
Specific Heat Capacity (C)
The amount of heat needed to raise one kilogram of a substance to 1C°
Explain how heat flows in the picture
Phase Changes
• The term phase is used to describe the specific state of matter.• A transition from one phase to another is
called a phase change or phase transition.
Phase Change
• Heat of fusion (Lf)- the heat required per unit mass in changing solid to liquid
• Heat of vaporization (Lv)- the heat required per unit mass in changing liquid to gas
• Heat of combustion (Lc) - the heat required per unit mass in complete combustion of one gram of gasoline
Mechanisms of Heat transfer
• Conduction occurs between a body or between two bodies in contact.• Convection depends on motion of mass
from one region of space to another.• Radiation is heat transfer by EM
radiation
Related Documents
