Transfer of heat and its effects Flashcards
What is the SI unit for temperature?
Kelvin (K)
What happens if objects are heated up?
They expand and its called expansion
What happens if objects are cooled?
They contract and its called contraction
How does an object expand?
When an object’s temperature increases, particles gain energy and vibrate more and move further apart. Hence the volume of object increases
How does an object contract?
When an object’s temperature decreases, particles lose energy and vibrate less and move closer together. Hence the volume of object decreases.
What is bimetallic strip?
It is a strip of two different metals
How does a bimetallic strip work?
When two different metal strips
are fixed together, the strip will
bend when heated or cooled. Brass expands more than steel,and becomes longer and the strip will bend. The bending is reversed when the strip cools.
Heat transfers from an area of lower/higher temperature
to an area of lower/higher temperature.
Heat transfers from an area of lower temperature to an area of higher temperature.
What is conduction?
Conduction is the transfer of heat energy without the physical movement of the medium.
How does heat gets transferred through conduction?
Firstly, heat is added to object.
As the molelucules gains heats, it vibrates fasters and knocks into neighbouring molelucules and heat is passed on.
What is the similiaries and differences between conduction and convection?
-Both have mediums
-Convection’s medium is liquid while conduction’s medium solid
-Conduction has no flow of medium while convection has a flow of medium
What is convection?
Convection is the transfer of heat from one place to another by the physical movement of a
medium. The medium has to be a fluid.
How does heat get transferred through convection?
As water gets heated, it becomes less dense. This causes the things placed in the water to rise up towards the surface of the water. The cooler water is then denser and sinks with the rice grains.
