Your car has been setting out in the hot summer sun all day. The metal hood, the glass windshield, and the fabric upholstry are all at 180 degrees farenheit. If you touch the hood with your hand it could be burned, if you touch the windshield it will be very hot, if you touch the seat it will be very warm. Why is there a difference in how the different objects feel if they are all the same temperature?

The reason why the different objects feel different even if they are all at the same temperature is because of their varying thermal conductivity. Thermal conductivity refers to the ability of a material to conduct heat.

In this case, the metal hood has a high thermal conductivity compared to the glass windshield and fabric upholstery. This means that the metal hood can transfer heat more efficiently from its surface to your hand. When you touch the hot metal hood, the heat is rapidly conducted from the metal to your skin, making it feel much hotter and even potentially causing burns.

On the other hand, glass has a relatively lower thermal conductivity than metal. When you touch the glass windshield, it takes a longer time for it to transfer heat to your hand. Although it is still hot, the heat transfers more slowly, resulting in a sensation of warmth rather than an immediate burning feeling.

As for the fabric upholstery, textiles typically have even lower thermal conductivity compared to metal and glass. Therefore, the heat transfer from the hot upholstery to your hand is much slower. While it may still feel warm, the slower rate of heat transfer gives the impression that the fabric is not as hot as the metal or glass.

In summary, the difference in how different objects feel at the same temperature is due to their varying thermal conductivity, which affects the rate of heat transfer to your hand when in contact with these objects.