Did you know that a material can be hot and cold at the same time? Hi! My name is Vitor And today we are going to find out that hot and cold could be a little tricky.
But first, subscribe to our channel Turn on notifications for you to be notified when we have new videos And if you like it, click the LIKE button. And subscribe to our Creative Scientist Club Just point your phone camera to the QR code next to me And we will deliver to your home great activities of eletronics, robotics, biotechnology And if you use this coupom you will get 10% off the first month. Hey Carol, tell me, if i place one hand on the wood and the other one on the metal which will be colder?
The metal? Looks like it, right? WRONG!
They are both at the same temperature Metal feels colder because it steals more heat from our hand. Do you doubt it? I am going to make an experiment so you can feel it on your own skin.
Materials cloth towel three basins with water Put ice on the first basin Put warm water on the third basin WARNING Ask for help from an adult to heat up the water Place water at room temperature in the middle basin Place one hand in the basin with cold water And the other hand on the basin with warm water Wait for your hands to get used to the temperature Dr both hands well And place them both at the middle basin This hand is going to feel the water warm And this hand is going to feel the water cold How did that happen? This happened due to the heat exchange between our hand and the water And this is called thermodynamics We usually say that it is a hot day but do you know what "HEAT" is? No!
Heat is not the same thing as temperature. Now imagine that you have one basin with warm water and one with cold Just like our experience But different from it, imagine if we mix both waters, what do you think is going to happen? The result will be water with an intermediate temperature between both waters This happens because the hot water has more energy All its molecules are very agitated While in cold water, not so much The hot water bumps into the colder one Making it move a little more and heat up a little bit But this bump makes the hot water gets less agitated And it cools down This happens until all the molecules are agitated equally And this movement that energy makes from the warmest water to the coldest water is called HEAT Do you get it?
Lets return to our experiment When we place our hand on the hot water, it raises temperature because it is receiving heat An when we place our hand on the cold water, it drops temperature because it is losing heat And when we put both hand on the middle basin The hot hand starts to loose heat to the water while the cold hand is receiving it That is why it feels like the same water has two different temperatures at the same time. Because our hands, that feel the heat, are at the same time giving and receiving energy from the water Everytime we give energy, we feel cold And when we receive it, we feel hot Really nice, right?
