I am abit confused between absorbers, radiators, conductors and insulators.
1)Books always wrote that "Water is kept warm in shiny kettle as shiny surface is poor radiator of heat". But why can't we use "absorber"? Isn't it absorbing more important?
2)Can we say that poor conductors will be poor absorbers and good conductors will be good absorbers?
I encounter one quriky question from assessment books . They say" Cold water is place in two containers one made up of metal and the other plastic" and ask "which water in the container will increase it temperature more". Is there anything wrong with the question? I don't understand why the materials concerning conduction is asked for radiation.
1)Books always wrote that "Water is kept warm in shiny kettle as shiny surface is poor radiator of heat". But why can't we use "absorber"? Isn't it absorbing more important?
Absorber and radiator are basically the same thing. When the heat is higher than surroundings, the object can only radiate heat. When the heat is lower than surroundings, the object can only absorb heat. There's no two ways about this.
So to keep water warm, a good "absorber" will actually become a good radiator of heat and radiate the warmth away from the water.
2)Can we say that poor conductors will be poor absorbers and good conductors will be good absorbers?
You mean electrical conductors vs heat conductors right? Usually yes, especially for metals. That's because metal has free electrons which can help conduct heat rapidly from one end to the other.
I encounter one quriky question from assessment books . They say" Cold water is place in two containers one made up of metal and the other plastic" and ask "which water in the container will increase it temperature more". Is there anything wrong with the question? I don't understand why the materials concerning conduction is asked for radiation.
Is that the full question or partial question? Any pictures to go along?
Originally posted by Hmyatthazin:1)Books always wrote that "Water is kept warm in shiny kettle as shiny surface is poor radiator of heat". But why can't we use "absorber"? Isn't it absorbing more important?
also, i think this is just english la. You can turn it around and say like "Water is kept cool in shiny kettle as shiny surface is poor absorber of heat" since heat isn't radiating out of the kettle.