Comparing The Zeroth And First Law Of Thermodynamics

The Zeroth and First law of Thermodynamics

The zeroth law, the first law, the second law and the third law of Thermodynamics are the four laws that govern the movement of heat between objects. The zeroth law of thermodynamics states that the temperature of two objects begins to change and after a certain amount of time the change stops at which point the objects are said to be in thermal equilibrium. Putting together two objects at different temperatures will cause the temperature of the hottest object to cool and the temperature of the cooler object will gain temperature making both object in thermal equilibrium. Symbolically it is represented: If object A is in thermal equilibrium with object B and object B is in Thermal equilibrium with

For example, imagine instead of having a container where none of the sides can move rightward and the container is completely rigid, nothing can move, imagine the top of the container being such that it has a tightly fitted piston and imagine, it can move up and down. In other words the piston can change the volume in which the gas gets to play in and the piston can move up or down. What can happen is that we can add energy just exerting a big force downward and compress the gas into a smaller and smaller region we said that the gas when it hits the faster moving molecules in the wall get to kick. The same is true in this example, we can take the gas molecules and imagine we are pushing the piston down when it collide appear with the piston that moving downward and again to get to kick and it starts moving faster, it gains energy manifesting itself as translational kinetic energy, rotational kinetic energy or energy vibrational regardless it 's all internal energy. We are exerting a force and this force is exerted over a certain amount of distance if we are pushing down and we know a force times distances. We are doing work and that is how we are adding energy into the gas. Work is being done by pushing the piston down and if we do work in the gas that means we are adding internal energy to the gas and the value of the work is the amount of energy we are trying to add to the internal energy of the gas. These are the two common ways that can be used to add internal energy to a gas and the formula version to the first law of thermodynamics is represented ∆U= Q+W. Where Q is the heat and W is the work done on the gas.

An important point is the work done on a gas having a plus sign in the formula is because by doing work on the gas means we are adding energy to the internal energy,