Idea 4of 9Builds onEnergy on the move
The warm air rises
Heated from the bottom, how does the top warm?
Today you'll discover
- how a pot of water warms all the way to the top
- what actually rises, and what does not
- the name for energy carried by a moving fluid
Think firstA pot of water on a burner, heated from below
A burner heats the bottom of a pot of water. How does the water at the top warm?
Decide first, then press Next. Follow the arrows: up the middle, down the sides.
A pot of water on a burner with arrows inside the water. After a prediction, the water at the bottom is picked out warming, then arrows show warm water rising up the middle and cooler water sinking at the sides, then the whole loop is named. The last step asks why a ceiling heater leaves your feet cold.
See the whole ideathe big idea and the key word, in one place
The big idea
Convection: a warm fluid rises, carrying its energy round.
Easy to get wrongThe saying should be warm AIR rises. Heat has no direction; it goes from hot to cold any way it can. A fluid that is lighter when warm floats upward.
Key word
- convection
- the transfer of thermal energy by the movement of a fluid, warmer and less dense parts rising while cooler parts sink
About this modelParticles are drawn far apart and the arrows show energy, not matter, except in the convection loop where the fluid itself moves.
Particles are drawn far apart and the arrows show energy, not matter, except in the convection loop where the fluid itself moves.
Ready to use it?
- Explain where to put a heater or a cooler in a room, using the loop.