Physics Course/Heat< Physics Course
Sources of Heat
Generally, Heats come from different sources
- Fire .
- Chemical Reaction between two flammable or combustible materials
- Celestial Body's Lights
- Sun light produce Heat as a Light of hot temperature. Moon Light produce Heat as a Light of Cold Temperature
- Electric Light
- Conductors when conduct current will change their body temperatures and release Heat Energy and Light
Heat is caused by friction . When rubbing two objects the object bodies will change in temperatures which produces Heat .
Temperature is a measured of Heat denoted as T measured in Degree . There are three system of temperature measurements namely Degree C , Degree F , Degree K
System of Measuring Temperature Temperature of Freezing Point Temperature of Boiling Point Room Temperature Degree C 0o 100o 25o Degree F 32o 212o 77o Degree K 273.16 373.16 298.16
Heat and Matters
An object when absorbs heat exhibit the followings
- Change in object's Temperature
- Change object's state or form
- Release Heat's Energy in the surrounding as Light
When an object absorbs Heat's Energy, it will change its temperature and either expand or shrink itself.
- For example, Electric wire shrink in the winter and expand in the summer .
Thermodynamic Law of Heat Transfer
First Law of Thermodynamic
When an object absorbs heat's energy it will expand or shrink
- If an object has a Mass m at the normal temperature of To . When this object absorbs heat's energy it will change its body temperature to T . Therefore the change in temperature of the object is T - To . If the object has an absorption constant of C then Heat Transfer can be calculated as
- Q = m C (T - To) = m C ΔT
Second Law of Thermodynamic
Heat transfer from objects that has a high temperature to object that has a low temperture
- E = 0 When
- E > 0 When
- E < 0 When
Heat comes from differenct sources namely Fire , Light , Electric or from collision of two objects . Temperature is a measured of Heat denoted as T measured in Degree .
There are three system of temperature measurements namely Degree C , Degree F , Degree K
System of Measuring Temperature Temperature of Temperature of Room Temperature Degree C 0o 100o 25o Degree F Degree K
The laws govern Thermaldynamic of Heat transfer are listed in the table below
Thermodynamic Law Heat Transfer Formula Thermodynamic First Law Heat is absorbed by matter that either make matter to shrink or to expand Q = m c (T - To) Thermodynamic Second Law Heat transfer from High temperature to low temperature . From Hot to Cold E = Q1 - Q2 khi T1 > T2
E = Q2 - Q1 khi T2 > T1