You have left your bicycle outside in the backyard for three hours on a very cold day. Now you decide to go for a ride. The metal handlebars feel colder than the plastic hand-grips because:
Question 4 options:
A) The latent heat of fusion of the plastic is bigger than the latent heat of fusion of the metal.
B) Metal objects are always colder than plastic objects, even when they have been left for several hours in the same surroundings and are at the same temperature.
C) The metal will react chemically with your skin, whereas the plastic does not.
D) The metal conducts heat away faster from your flesh than the plastic does, even though both are at the same temperature.
The first three answers are ridiculous, aren't they?
The correct answer is D) The metal conducts heat away faster from your flesh than the plastic does, even though both are at the same temperature.
When an object is left outside in a cold environment, it will eventually reach the same temperature as its surroundings. In this case, both the metal handlebars and the plastic hand-grips have been exposed to the cold temperature for the same amount of time.
However, metal is a better conductor of heat than plastic. This means that when you touch the metal handlebars, heat from your body is transferred to the metal more quickly compared to the plastic hand-grips. As a result, when you touch the metal handlebars, you will feel a sensation of coldness because the metal is effectively drawing heat away from your skin at a faster rate.
On the other hand, the plastic hand-grips are poorer conductors of heat, so they do not draw heat away from your skin as quickly as metal. Therefore, the plastic hand-grips will feel warmer to the touch in comparison to the metal handlebars, even though both are at the same low temperature.