8.2 Heating and cooling Flashcards
define temperature
a measure of how hot or cold something is. It is the average amount of thermal energy in a substance.
define thermal energy
energy stored in an object due to its temperature
Does thermal energy move from hot objects to cooler objects or from cool objects to hotter objects?
from hot objects to cooler objects
Which has the most thermal energy, a litre of water at 30°C or 200cm3 of water at the same temperature? Explain your answer
A litre of water. This is because it has more particles.
Why are thick curtains not used to stop the cold coming in?
As thermal energy goes from hot to cooler objects, the curtains are used to prevent the heat from escaping.
Why does putting you hand into hot water burn but cool water doesn’t?
In hot water, the heat transfers to your hand, burning it. In cold water, the heat from your hand transfers to the water instead. The average kinetic energy of the particles is much more in hot water than cold water.
Why shouldn’t you put hot objects into a fridge?
The heat from the hot object will transfer to the other objects in the fridge causing the fridge’s temperature to increase.
