Unit 11.Thermal energy transfer

04.29.2020
09:34:34
Dear students, good morning
Today's topic in physics: radiation
Pg.no : 155 & 156
The important points are
1. The light that reaches us from the sun and other stars travels us through space in the form of electromagnetic radiation.
2. Characteristic of infrared radiation :
* is produced by warm or hot objects.
* Is a form of electromagnetic radiation
*. Travels through the empty space in the form of waves
*. Travels in straight line
* Warms the object that absorbs it
*.is invisible to the naked eye.
* Can be detected by nerve cells in the skin.
Look at figure 11.11
3. Good absorbers and good emitters:
* Shiny or while surface are the best reflectors
* Matt balck surface are the best absorbers and the best emitters.
Look at figure 11.13
No homework
For better understanding of concepts watch the below videos