Work Done by a Gas

 This simulation illustrates the concept of work done by a gas in a variety of processes. Unlike the solids and the liquids, gases can change their volume considerably, and are capable of producing mechanical work. If the gas volume is changed by ΔV, the amount of work produced is W = PΔV, where P is the gas pressure. During expansion, the gas produces positive work. During compression, other bodies produce work on the gas, which translates into gas producing negative work. An amount of work is a function of the gas' transition from the initial to its final state. You can select different kinds of work-to-gas dependence ratios p(V) (linear, square or exponential), and to determine work done by the gas. Note that work is quantitatively equal to the area under the curve that represents the process on the (p, V) diagram. On the energy diagram, observe the quantity of heat obtained by the gas Q, the amount of work produced W, and the change of internal energy ΔU for a given process. Note that the amounts of heat and work depend on the type of transition from the gas' initial to final state. The change in internal energy does not depend on the process, and is determined only by the initial and the final states of the gas.