# Coffee Cup Coffee

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The topic under discussion is “What type of coffee cup is the best at keeping your coffee hot the longest?” This experiment highlights how heat travels and the insulating properties of three types of materials three of which are the cups being paper (cardboard), ceramic and stainless steel. The aim is to clearly identify which cup insulates heat the best and for the longest amount of time. The hypothesis is that if the material can trap the most air the then the better the insulation. It is expected that the outcome of these three materials that the thermos (stainless steel) will be the best insulator as it has a more complex design that is best suited to insulate for the longest period of time. 250mL of hot water is in each cup that has the…show more content…
Meaning that all bodies will eventually meet thermal equilibrium. The greater the difference in temperature between the object and its surroundings, the faster the object will cool and when the object’s temperature and the ambient temperature are closer, then the object will cool down more slowly. The equation dT/dt=-k(T-Ta) can be used to find the rate the temperature decreases or increases, where dT is change in temperature of an object, dt is change in time, k is a constant and Ta is ambient temperature. The constant k is an indication of the surface properties, for example, heat capacity. It also includes external factors such as humidity, which are aimed to be controlled. The higher the k value the greater the change in temperature thus the material is a poor insulator. The rate can be approximated by the equation dT/dt, which is basically the gradient (T_2-T_1)/(t_2-t_1 ), from these k values it can also be estimated to find the average…show more content…
As stated by BBC, the design is basically one cup inside another and because of this air is removed from the space in between these two cups that create a near vacuum. This near vacuum limits heat transfer by conduction and convection because there it is an empty space therefore fewer molecules are able to move. Generally, there the inside is coated with a reflective material, known as silver that reduces heat loss through radiation. The bonding in a thermos cup is metallic as steel is a