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?

because they are all made of different materials therefore they will each retain heat more or less.

The nerves in our skin do not sense temperature, they sense heat flow. If heat flow is great, we sense it as hot. If heat flow is outward, we sense it as cold.

The seat has stored little heat, so touching it wont get much heat flow. The windshield actually has stored more heat than the hood, but because it is a very poorconductor not much heat will flow to the skin nerves. Now the hood, is a moderate store of heat, but a great conductor, so heat flows, skin says "very hot".

Hannah, please do not impersonate teachers. Thanks

Although the three objects in question are at the same temperature of 180 degrees Fahrenheit, they may feel different when touched due to their different thermal conductivities and specific heat capacities.

Thermal conductivity refers to how easily heat can transfer through a material. Metal, such as the car hood, is a good conductor of heat, meaning it can readily transfer heat to your hand upon contact. Therefore, even though the metal itself is at 180 degrees Fahrenheit, it can still burn your hand because it rapidly transfers heat to your skin.

On the other hand, glass, like the windshield, is not as good of a conductor compared to metal. So, while it is still very hot, it may not conduct heat as efficiently as metal, resulting in a lesser feeling of burning. However, it can still feel very hot to the touch due to the heat being trapped within the glass.

Lastly, fabric upholstery has a lower thermal conductivity compared to both metal and glass. This means it is less efficient in transferring heat. Therefore, even though the seat is also at 180 degrees Fahrenheit, the fabric does not rapidly transfer heat to your hand like the metal hood. Consequently, it may feel warm rather than burning hot.

To summarize, the difference in how the objects feel when touched, despite being at the same temperature, is due to variations in thermal conductivity. Metal transfers heat efficiently, glass retains heat but conducts it less efficiently, and fabric upholstery has even lower conductivity, resulting in different sensations when touched.