convection Flashcards
What uses convection to stay in the air?
Glider aircraft and birds
When does convection happen?
When fluids (liquids and gases) are heated
How does convection work in the hot water tank in homes?
Hot water from the boiler rises and flows into the tank where it rises to the top. When using a hot water tap at home, the hot water is drawn off the top of the tank
How is convection in play during sea breezes?
On a sunny day, the ground heats up faster than the sea. So the air about the ground warms up and rises. Cooler air from the sea flows in as a ‘sea breeze’ to take the place of the rising warm air
What does convection take place in?
Only in fluids (liquids and gases)
Why does convection happen?
Because of circulation within the fluid
In detail, why does convection occur?
Fluids rise when they are heated because heating them makes them less dense. Then they stop rising where they cool down, because cooling makes them more dense. Convection streams transfer energy from the hotter parts to the cooler parts
Why do fluids rise when heated?
Most fluids expand when heated. This is because the particles move about more and they move apart, taking up more space. Therefore the density decreases because the same mass of fluid now occupies a bigger volume
