If u reach into a hot oven to remove a pizza, ur arm is not burned by the hot air but would be burned if u touched the pan. Explain.
If u reached into a hot oven to remove a pizza, ur arm would not get burned by the hot air, instead it would get burned if u touched the pan because the particles of the pan are in vibration and so if u touch the it, the heat from the particles in the pan touches the colder particles of ur jand and ur hand absorbs the heat from the pan, these particles spread little and make surrounding particles of ur hand vibrate too. That's how u can get a burn which turns out to be bigger than the point at which ur hand actually touched the pan. This is conduction. The warm air coming out of the oven would be convection.
Both the pan and the hot air are at the same temperature. But much more heat is contained in the pan (it has a much higher specific heat capacity than air).
So getting a burn means you absorbed heat: the pan has more to offer.
Worse yet, if you were scalded with hot water. Gram for gram, water stores about 10 times as much heat as aluminum (at the same temperature),this is why hot water is very dangerous.
thanks for the information bobpursley, ill keep all that in mind, thanks a bunch:)
When you reach into a hot oven, the first thing to understand is that heat is transferred through three main mechanisms: conduction, convection, and radiation.
In the case of your arm not being burned by the hot air, it is because of the principle of convection. Convection is the transfer of heat through the movement of a fluid, such as air. In this scenario, the hot air inside the oven is the fluid. As you open the oven door, some hot air will naturally escape from the oven and make contact with your arm.
However, the heat transfer through convection is relatively inefficient compared to the other mechanisms. The air molecules are quite spread out, so there is less contact between the hot air and your skin. Additionally, air is a poor conductor of heat. So, even if the air is hot, it won't conduct heat as effectively as a solid object, like the pan.
On the other hand, if you were to touch the pan, you would experience a burn. This is because the pan, being a solid object, conducts heat much more efficiently than air. When you touch the pan, the heat from the particles in the pan transfers to the colder particles in your hand. These particles then spread the heat, causing surrounding particles in your hand to vibrate, leading to a burn. This process is known as conduction.
In summary, your arm does not get burned by the hot air because convection is less effective at transferring heat compared to conduction. When you touch the pan, however, the solid object conducts heat more efficiently, leading to a burn.