It also contains a hot body connected to the bottom. This hot body is important in conduction because remember, conduction requires for physical contact between two systems. And conduction allows heat transfer or energy transfer from a hot object to a cold object. So let's see what the result is of constant pressure. From this formula we see that kinetic energy is related to KB, which is a constant and number of particles and T temperature. Now, the number of particles remains constant because this is a closed system.