Page 39 - Finalll Science BB Prep2 t1 2025_Neat
P. 39
Radiation
The sun’s heat is transferred to us without the need for material
particles “despite the millions of km diff.”
Solar radiation consists of many electromagnetic waves, some is
visible as light & other is invisible as IR infrared rays have thermal effect.
Dark opaque objects absorb IR better than light colored / shiny objects.
▪ Firefighters wear shiny silver uniforms.
▪ In summer, we wear white / light colored clothes.
▪ In winter, we wear dark colored clothes.
▪ Solar heater pipes are painted in black.
• All hot objects & thermal sources emit heat (IR) is transferred by
convection & radiation but sun rays are transferred by radiation
only.
First Term 66
