Hot water rises
Cooler water sinks
Cools at the surface
Why is it windy at the seaside?
Cold air sinks
Where is the freezer compartment put in a fridge?
It is put at the top, because cool air sinks, so it cools the food on the way down.
It is warmer at the bottom, so this warmer air rises and a convection current is set up.
The third method of heat transfer
How does heat energy get from the Sun to the Earth?
There are no particles between the Sun and the Earth so it CANNOT travel by conduction or by convection.
Radiation travels in straight lines
Radiation can travel through a vacuum
Radiation requires particles to travel
Radiation travels at the speed of light
Four containers were filled with warm water. Which container would have the warmest water after ten minutes?
The container would be the warmest after ten minutes because its shiny surface reflects heat _ back into the container so less is lost. The container would be the coolest because it is the best at _ heat radiation.
Four containers were placed equidistant from a heater. Which container would have the warmest water after ten minutes?
The container would be the warmest after ten minutes because its surface absorbs heat _ the best. The _ container would be the coolest because it is the poorest at heat radiation.
Why are boilers placed beneath hot water tanks in people’s homes?
Hot water rises.
So when the boiler heats the water, and the hot water rises, the water tank is filled with hot water.
Why does hot air rise and cold air sink?
Cool air is more dense than warm air, so the cool air ‘falls through’ the warm air.
Why are houses painted white in hot countries?
White reflects heat radiation and keeps the house cooler.