Why does Han Solo (in carbonite) melt faster on the dark block compared to the lighter block? How is it, that blocks of the same colour and temperature cause ice cubes to melt at different rates?
Students explored these blocks and found the following:
Dark Black Block
- Felt cool to the touch
- Was heavier than the other block
- Was the SAME temperature as the other block
- Did NOT feel cool to the touch
- Lighter than the dark block
- SAME temperature as other block
So, if the two blocks have the same temperature (since they are in the same room and are not being heated or cooled), why then did the darker block cause the ice cube to melt faster than the other lighter block?
Answer: It comes down to which is the better heat conductor!
Conductors transfer (pass on) heat from one object to another with greater efficiency, while insulators do NOT transfer heat effectively.
Think about when you touch a handle when you cook, those pots that have a metal handle are hotter than those with a plastic handle. That is because the heat gets transferred from the pot into the handle easier than into a plastic handle.
The Black tile is made from Aluminium, which a great heat conductor. That is why it feels cool when you touch it, the heat from your hand travels from your hand into the block. That makes you ‘feel’ like the block is cooler because your hand is loosing heat to the block. The other block is a black plastic which is an insulator. That means, little heat is lost by your hand to the block and it doesn’t ‘feel’ as cool because the heat stays in your hand.
What about the Ice Cube?
Ice melts when it absorbs heat…. this is called an endothermic process. (heat is going from the surroundings into the ice cube and increasing the movement of the water molecules which makes the ice crystal break and …melt)
The heat from the ice is transferred into the Aluminium block easily and thus the block melts really fast, however, for the plastic block (the insulator) little heat is lost from the ice into the block and therefore the ice cube takes a lot longer to melt.
Until next time, keep experimenting!